CN109314901B

CN109314901B - Apparatus for multiple connectivity support and fast cell handover

Info

Publication number: CN109314901B
Application number: CN201680086744.7A
Authority: CN
Inventors: 朱京; 纳吉恩·海玛亚特; 李旭峰; 萨拉博乔特·辛格; 伊赫桑·阿亚法尔
Original assignee: Apple Inc
Current assignee: Apple Inc
Priority date: 2016-07-13
Filing date: 2016-07-13
Publication date: 2022-02-01
Anticipated expiration: 2036-07-13
Also published as: CN109314901A; WO2018013110A1

Abstract

Embodiments relate to a User Equipment (UE) in communication with an evolved node b (enb) on a wireless network, the UE including one or more processors to: connect/communicate with at least a first anchor eNB and a second booster eNB; maintaining a plurality of radio access network communication links between the UE and radio access networks of the wireless network, wherein the plurality of radio access network communication links between the UE and radio access networks of the wireless network includes at least one primary communication link and at least one secondary communication link; when it is determined that the at least one primary communication link is lost, switching from actively transmitting and receiving data for the UE using the at least one primary communication link to actively transmitting and receiving data for the UE using the at least one secondary communication link. Other embodiments may be described/claimed.

Description

Apparatus for multiple connectivity support and fast cell handover

Technical Field

Embodiments described herein relate generally to the field of wireless communication systems.

Background

Various wireless cellular communication systems have been implemented or are being proposed, including third generation partnership project (3GPP) Universal Mobile Telecommunications System (UMTS), 3GPP Long Term Evolution (LTE) system, 3GPP LTE-advanced system, and fifth generation wireless system/fifth generation mobile network (5G) system/fifth generation New Radio (NR) technology.

Some proposed cellular communication systems may incorporate radio frequencies including one or more frequency bands between 30 gigahertz and 300 gigahertz. These communication systems may sometimes be referred to as millimeter wave (mmWave) systems, corresponding to radio wavelengths from 10mm to 1 mm.

Drawings

Embodiments of the present disclosure will be understood more fully based on the detailed description given below and the accompanying drawings of various embodiments of the disclosure. However, while the drawings are intended to facilitate explanation and understanding, they are used merely to facilitate and should not be construed as limiting the disclosure to the specific embodiments described herein.

Fig. 1 shows a proposed multi-connectivity network architecture according to an example;

fig. 2 shows an example of a possible end-to-end (e2e) user plane protocol stack for the multi-connectivity network architecture proposed in fig. 1;

fig. 3 shows an example of a possible end-to-end (e2e) control plane protocol stack for the multi-connectivity network architecture proposed in fig. 1;

figure 4 shows a first alternative example of how PSS/SSS/SLS synchronisation signals from neighbouring cells may be distributed in a frame;

figure 5 shows a second alternative example of how PSS/SSS/SLS synchronisation signals from neighbouring cells may be distributed in a frame;

fig. 6 shows how a short broadcast (sBCH) may be allocated in a subframe with three sectors A, B, and C according to an example;

FIG. 7 shows how a persistent scheduling request message (qSR-REQ) and a persistent scheduling request response message (pSR-RSP) can be distributed in a specific subframe around existing content;

FIG. 8 illustrates how the pSR-REQ and pSR-RSP messages can be distributed in normal subframes around existing content;

FIG. 9 illustrates a high level flow chart of a method of detecting a loss of a communication link according to an example;

fig. 10 illustrates a portion of a method for a UE to detect primary communication link loss and resulting handover of its primary cell, in accordance with some examples;

fig. 11 illustrates hardware processing circuitry for a UE and an eNB, according to some examples;

fig. 12 illustrates an example implementation of an electronic device (e.g., a UE and an eNB) in accordance with some examples;

fig. 13 illustrates a pictorial representation of hardware resources, according to some examples.

Detailed Description

Millimeter wave (mmWave) systems have the potential to provide enormous bandwidths. mmWave systems may also be referred to as high-band systems or very high-band systems. Due to the potential bandwidth, mmWave systems are candidates for supporting future 5G systems. In some cases, mmWave small cells may be deployed in LTE-assisted "anchor boost" mode. In other cases, mmWave small cells may be deployed to operate independently (e.g., without assistance from LTE macro cells). A cell is a logical concept and may be referred to as a radio access network (or portion thereof). Depending on the particular cell provisioning architecture, the cells may be provided by a single evolved node b (eNB) and radio head or by multiple radio heads of the eNB. That is, the eNB is a physical device, and the eNB may operate one or more cells.

High-band systems, such as mmWave systems, may require directional beamforming by both an evolved node b (enb) (or Access Point (AP)/Base Station (BS)) and a User Equipment (UE) (or Station (STA)) in order to achieve a signal-to-noise ratio (SNR) that facilitates establishing a communication link for the used frequency. Accordingly, an initial acquisition procedure or access procedure may be used to enable the eNB and UE to determine the best Transmit (TX) and/or Receive (RX) beamforming direction (or beam) for establishing a directional connection. Since mmWave communication links are highly directional and sensitive to the environment, they are easily blocked (where blocked includes any way of disconnection or loss of the communication link between the UE and the eNB, i.e., including the UE no longer being able to communicate with the eNB at all (and vice versa) or simply not being at a level with sufficient predetermined performance). Examples therefore include a full blocking as well as a situation that is considered to be blocking, where communication performance falls below an acceptable (i.e., predetermined) performance level. To reduce the adverse effects of a lost communication link between the UE and the eNB, mmWave frequencies are utilized to communicate between the UE and the eNB. According to an example, a fast cell handover procedure may be provided to temporarily transition to an alternate (i.e., secondary) mmWave communication link that serves as a "hot backup" for the primary (i.e., primary) mmWave communication link, which may be used to minimize service disruption caused by congestion. In some examples, the primary or secondary communication link may be a Radio Access Technology (RAT) other than mmWave RAT.

Therefore, the described fast cell handover procedure is advantageous in designing mmWave systems or other high frequency band systems that are more flexible. The described fast cell handover procedure may utilize a Dual Connectivity (DC) procedure, using a (more robust) LTE communication link as anchor and a 5G mmWave communication link as boost. That is, the "hot standby" alternate communication link may be another mmWave communication link or a communication link of a completely different radio access technology type. In a Dual Connectivity (DC) procedure, the UE may maintain two communication links such that the UE's data traffic may be seamlessly shifted to the LTE communication link whenever a 5G mmWave communication link is temporarily lost.

In addition, the described fast cell handover procedure may also utilize multiple communication links (e.g., more than 2) simultaneously, in which case the fast cell handover procedure may be referred to as a Multiple Connectivity (MC) procedure to allow fast handover between multiple communication links. According to an example, mmWave cells may be (mutually) similar in coverage and reliability.

The described examples may provide processes and techniques that facilitate both standalone deployment (i.e., single anchor, with only the primary communication link active) and dual/multi-connectivity deployment (e.g., with anchor-boost arrangements, with both the primary and secondary communication links active, and potentially multiple uses of one or each). In each case, advantages include maximization of mmWave Radio Access Technology (RAT)/cell usage.

According to an example, although the principle based on dual connectivity may be used to allow the secondary cell to act as a backup communication link, examples also provide further optimizations in the radio network to address the problems caused by the directional access characteristics of mmWave based RATs.

According to an example, the provided optimization may support dual/multi-connectivity for mmWave-based radio networks, which may include extensions to a dual connectivity architecture.

In particular, according to an example, the following basic building blocks are proposed to enable high performance and efficient multi-connectivity and support fast cell handover between mmWave based RATs, in particular between mmWave cells (between different mmWave cells, and between mmWave cells and other 5G/LTE (i.e. non-mmWave) RAT cells). One key issue addressed by the examples described herein is the issue of how to switch to an alternative communication link at the UE, in particular how to efficiently switch to an alternative communication link, if/once the (original) primary serving cell of the user is blocked, resulting in a loss of the respective control link and data link.

Thus, the examples provide a novel multi-connectivity network architecture that is based on the dual connectivity principle but extends dual connectivity to multi-connectivity by including some key changes that address handovers of both control plane traffic and user plane traffic to secondary cells/enbs when the primary mmWave communication link is blocked. According to some examples, the secondary cells/enbs are advantageously used in a "hot standby" mode (i.e. a mode in which they can be used immediately).

Examples also provide a new method of coordinating Downlink (DL) synchronization and/or broadcast channels and/or Sector Level Scanning (SLS) between neighboring cells. In some examples, this may advantageously provide relaxed (i.e., valid only at the symbol level time frame) time synchronization.

Examples also provide any one or more of: a new DL broadcast channel, a new DL control channel, or a DL reference signal. Any one or more of these channels or signals may be advantageously used as a fast communication link loss detection mechanism.

The examples also provide a new approach to maintaining a low overhead control link by using any secondary cell/eNB, which advantageously allows fast handover when the control link of the primary cell is lost (note that, in general, if the control link is lost, it is no longer important whether the data link is still connected, since the UE loses the connection anyway). The term "low overhead" may be considered to refer to any system that uses a minimum (or near minimum) level of radio resources available in a respective Radio Access Network (RAN) or RAT.

Examples also provide for fast UE-based cell handover procedures.

Throughout this disclosure, current LTE terminology is used for entities including, for example, UEs, enbs, etc. This is done primarily to identify 4G/LTE nodes that may share similar logical/conceptual functions in 5G, but it will be understood that the actual (exact) names of these nodes in a 5G system have not been finalized in the 3GPP standards, so the disclosure is in no way limited to the specific terminology used. In the following description, numerous details are discussed to provide a more thorough explanation of embodiments of the present disclosure. However, it will be apparent to one skilled in the art that embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring embodiments of the present disclosure.

Note that in the corresponding drawings of the embodiments, signals are indicated by line segments. Some of the line segments may be thicker to indicate a greater number of constituent signal paths and/or have arrows at one or more ends to indicate the direction of information flow. These indications are not intended for limiting purposes. Rather, line segments are used in connection with one or more exemplary embodiments to facilitate easier understanding of a circuit or logic cell. Any signals represented may actually comprise one or more signals that may travel in any direction, as dictated by design requirements or preferences, and may be implemented using any suitable type of signal mechanism.

Throughout the specification and in the claims, the term "connected" means a direct electrical, mechanical, or magnetic connection between the things without any intermediate device. The term "coupled" means either a direct electrical, mechanical, or magnetic connection between the things that are connected, or an indirect connection through one or more passive or active intermediary devices. The term "circuit" or "module" may refer to one or more passive and/or active components arranged to cooperate with each other to provide a desired function. The term "signal" may refer to at least one current signal, voltage signal, magnetic signal, or data/clock signal. The meaning of "a", "an", and "the" includes a plurality of references. The meaning of "in" includes "in" and "on".

The terms "substantially", "close", "about", "approximately", and "approximately" generally refer to being within +/-10% of a target value. Unless indicated to the contrary, the use of the ordinal adjectives "first", "second", "third", etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than described or illustrated herein. The terms "left," "right," "front," "back," "up," "down," "over," "under," and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions.

For purposes of the embodiments, the transistors in the various circuits, modules, and logic blocks are tunnel fets (tfets). Some transistors of various embodiments may include Metal Oxide Semiconductor (MOS) transistors that include a drain terminal, a source terminal, a gate terminal, and a body terminal. Transistors may also include tri-gate and FinFET transistors, gate all around cylindrical transistors, square line transistors, rectangular strip transistors, or other devices that perform a transistor function, such as carbon nanotube or spintronic devices. The symmetrical source and drain terminals of the MOSFET are the same terminal and therefore are used interchangeably herein. TFET devices, on the other hand, have asymmetric source and drain terminals. It will be apparent to those skilled in the art that other transistors, such as bipolar transistors BJTs PNP/NPN, BiCMOS, CMOS, etc., may be used for some of the transistors without departing from the scope of the present disclosure.

For the purposes of this disclosure, the phrases "a and/or B" and "a or B" mean (a), (B), or (a and B). For the purposes of this disclosure, the phrase "A, B, and/or C" denotes (a), (B), (C), (a and B), (a and C), (B and C), or (A, B, and C). In addition, various elements of combinational and sequential logic discussed in this disclosure may relate to an optimized set of devices either physical structures (e.g., and, or, xor gates) or implementing Boolean (Boolean) equivalent logic structures as the discussed logic. In addition, for purposes of this disclosure, the terms "eNB", "AP", "5G eNB", "mmWave small cell", and "base station" may be substantially interchangeable. For purposes of this disclosure, "UE," "STA," "5G UE," "mmWave UE," and "mobile device" may be exchanged substantially. In various embodiments discussed below, the eNB and/or UE may be calibrated for directional reciprocity. Accordingly, the same beam (and/or sector) may be the best TX beam (and/or sector) and the best RX beam (and/or sector) and may have substantially the same exit angle and incident angle. Additionally, some embodiments discussed below may employ a Time Division Duplex (TDD) mechanism, but other embodiments may employ other mechanisms such as a Frequency Division Duplex (FDD) mechanism.

1: multi-connectivity network architecture

Fig. 1 shows a proposed multi-connectivity network architecture 100 according to an example. Examples are described in terms of entities and links used in the 4G/LTE standard, but the principles may equally be applied specifically to any other similar functional entity in existing or newly proposed 5G systems and mmWave systems. In fig. 1, there is a UE 110 connectable to an

eNB

120 and 140 via a Uu link 115, where Uu is the name of the standard radio interface between the UE and the eNodeB. Meanwhile, enbs are connected to each other via, for example, an X2 interface 135, where X2 is the name of a standard radio interface between enodebs. The eNB is connected to a serving gateway (S-GW)150 of the core network via a corresponding S1 link 145. The S-GW 150 connects to the rest of the core network via a Packet Data Network (PDN) gateway P-GW 160, via an appropriate link such as S5 or S8 link 155.

In the example shown, UE 110 may be connected to multiple enbs at the same time, in this case eNB # a120, eNB # B130, eNB # C140. In this figure, a multi-connectivity arrangement is shown, where there is a single anchor eNB (eNB # a 120) and two booster enbs (eNB # B130 and eNB # C140). Thus, in the present arrangement, the UE 110 has only one anchor eNB and all other enbs are booster, but other arrangements with multiple enbs of each eNB type (anchor or booster) or multiple enbs of at least one type (e.g. booster) may also be provided in other examples.

In this example, the anchor eNB # a120 is responsible for all (i.e., user plane and control plane) communications between the UE 110 and the core network (S-GW/P-GW/MME, etc.). The central S1 interface between the anchor eNB # a120 and the S-GW 150 is shown by the bold line in fig. 1. Meanwhile, the booster eNB (# B130/# C140) is responsible only for communication with the UE in the RAN (i.e., is responsible only for UE-to-eNB communication).

In the disclosed example, UE 110 may have multiple RAN connections, where a RAN connection is a communication link from the UE to a (possibly different) eNB. Although the anchoring eNB will always control the UE's primary link to the core network, the UE's RAN communication link may be classified as either a primary communication link 180 or a secondary communication link 190.

UE 110 uses its primary communication link 180 to send and receive data traffic and its secondary communication link 190 as a backup in the event of loss of any of its primary communication links. If UE 110 has multiple primary communication links, the data traffic of UE 110 may be divided over the multiple primary communication links, i.e., one bearer division may be implemented. In the case where UE 110 uses a secondary communication link, corresponding user-plane/control-plane data may be sent to anchor eNB 120 via a corresponding X2 link (i.e., forming an indirect link from UE 110 to the core network).

As mentioned above, the way to observe the newly proposed system of fig. 1 is to decouple the legacy anchoring functionality connected to the core network from the legacy anchoring functionality providing the air interface to the UE (arranged according to the usual anchoring-boosting type). In this way, multiple secondary communication (air interface) links between the UE 110 and respective (secondary, boost-type) enbs (e.g., # B130, # C140) may be used via the X2 link 135 (each secondary communication link being carried to an anchor eNB (e.g., # a 120)). Another observation is that there is a single entry point/path to/from UE 110 from the core network perspective, but multiple entry points/paths to/from UE 110 from the UE perspective. The following description and examples herein detail how such an arrangement may provide benefits and may be used to provide new functionality not available with previous directional communication systems.

Fig. 2 shows an example of a possible end-to-end (e2e) user plane protocol stack 200 for the multi-connectivity network architecture proposed in fig. 1.

In this figure, UE 110 is shown connected to three enbs (anchor eNB # a120 and two booster enbs # B130 and # C140). Anchor eNB # a120 serves as the primary/unique link for the UE to the core network (i.e., all other UE traffic served by other booster enbs in the RAN still must be routed through the anchor eNB). The booster enbs (# B130 and # C140) are only used to provide RAN access to the UE and send all UE traffic to/from the core network via the anchor eNB # a120 (via, for example, X2 interface 135).

The UE is connected to each eNB via a respective one of the usual UE-eNB interfaces (commonly referred to as the Uu interface) 115. The enbs are interconnected by a common eNB-to-eNB interface, commonly referred to as the X2 interface.

In a UE 110 according to the present disclosure, a novel multi-connectivity control entity is provided in a protocol stack known as a multi-connectivity convergence protocol. This is shown for the UE (for the user plane part) as entity MCCP-u 111. It is located in the protocol stack of the UE, between the IP layer and the PDCP layer (three are shown in the figure, but there may be more or fewer in other embodiments) for each connection used.

A similar supplementary eNB-side MCCP-u entity 121 is shown in anchor eNB # a 120. In the user plane (i.e., user data), the MCCP-u protocol entities are not needed in the booster enbs as they only communicate data to the anchor eNB under the control of the MCCP-c control entity discussed below.

The remaining protocol entities disclosed, e.g., PDCP, RLC, PHY/MAC, GTP-U, UDP, and IP entities, all operate in their usual manner and are therefore not described in further detail herein.

Fig. 3 shows an example of a possible end-to-end (e2e) control plane protocol stack 300 for the multi-connectivity network architecture proposed in fig. 1. As shown, UE 110 and each eNB now also includes a multiple connectivity convergence protocol control plane layer entity (MCCP-C) shown as UE MCCP-C112, eNB # A MCCP-u 122, eNB # B MCCP-C132, and eNB # C MCCP-C142, respectively. These MCCP-c entities are provided at each location, as control of data flow and control flow can be performed (or at least implemented) at any or all of their locations. In addition, the remaining protocol entities disclosed, e.g., NAS, PDCP, RLC, PHY/MAC, GTP-U, UDP, IP, and RRC entities all operate in their usual manner and are therefore not described in further detail herein.

In these figures, UE 110 may transmit or receive data traffic via its anchor eNB 120, either directly or via its booster enbs (130, 140), which then communicate with anchor eNB 120 over X2 interface 135. The proposed multi-connectivity convergence u-plane protocol (MCCP-u) operates on/above the respective RAN stack (above the PDCP) and it can manage how data traffic for the UE 110 is routed over multiple main links 180. Unlike the 3GPP R13 dual connectivity scheme, all communication links between a UE and a respective eNB (i.e., primary and secondary Uu links) have their own complete user plane and control plane stacks and can therefore operate independently of each other. In some examples, support for the aforementioned PDCP bearer splitting in the proposed MCCP may be provided. Additionally, in some examples, neighboring enbs may cooperate with one another, e.g., via an X2 application protocol, where an X2 application protocol may run over an X2 interface between enbs.

2: inter-cell coordination and Sector Level Scanning (SLS) for synchronization

Since achieving tight symbol-level synchronization between mmWave cells may be difficult, examples may have all neighboring mmWave cells cooperating with each other to maintain a fixed offset when each SLS is allocated in neighboring enbs, i.e., to provide what is referred to herein as an "SLS start offset". The following is a description of the above "SLS start offset". Use of D_kTo indicate the "SLS start offset" for cell # k, where:

D_k＝k x T_offsetwherein k is 1 to N (1)

According to an example, the eNB should broadcast parameters (k, N, T) to the UE 110 as part of the system information transmitted in the DL control channel_offset) So that UE 110 knows in which superframe/frame/subframe the corresponding synchronization signal (e.g., Primary Synchronization Signal (PSS)/Secondary Synchronization Signal (SSS)/Sector Level Sweep (SLS) signal) can be transmitted in its neighboring cells. If the neighboring cells are closely synchronized at the Cyclic Prefix (CP) level, UE 110 can synchronize with all neighboring cells simultaneously with the same clock, and we can configure T_offset0, so that SLS signals from neighboring cells occur simultaneously. Tight synchronization may be defined as any time difference between cells/enbs of symbol or less, e.g. 10% of the symbol transmission time.

Conversely, if cells are loosely synchronized at the symbol level (which is a more likely use case scenario), UE 110 may maintain separate clock and timing mechanisms for each cell/eNB to which it is connected. In this case, T_offsetMay be configured to a value greater than 0 such that UE 110 may perform SLS for different cells at different times, i.e., this may provide a form of time division duplexing (TDM) for SLS processing. In this case, N determines the maximum number of enbs to which UE 110 may simultaneously connect. Figure 4 shows how PSS/SSS/SLS signals from neighbouring cells may be distributed with N-3 and T_offsetA first optional example in a frame of a subframe of 1.

In particular, fig. 4 shows a timeline of how PSS, SSS, and SLS signals may be allocated in neighboring cells. In fig. 4, we show SLS (sector level sweep) allocations for UE (receiver) sector sweep signals (RXSS) and eNB (transmitter) sector sweep signals (TXSS), respectively, where PSS 422/432/442 and SLS 428/438/448 are eNB (transmitter) sector sweep signals (TXSS) and SSS 424/434/444 and SLS 426/436/446 are UE (receiver) sector sweep signals (RXSS).

Initial acquisition is performed using PSS and SSS signals, and SLS signals are used after the initial acquisition is successfully completed and the respective UE is attached. In this example, note that all PSS signals (e.g., PSS 422/432/442) always occur before SSS signals (e.g., SSS 424/434/444). Previously, UE RXSS occurred during SSS and eNB TXSS occurred during PSS. However, in this example, all PSS or SSS in adjacent cells occur simultaneously, with the corresponding SLS at a fixed time offset T_offset435 (for higher numbered cells, by a multiple of a fixed time offset, e.g., 2T_offset445) And occurs. Note that the PSS/SSS signals are only needed during initial acquisition and this is why they occur in the same subframe (e.g., the first subframe).

Figure 5 shows how PSS/SSS/SLS signals from neighbouring cells may be distributed with N-3, T_offsetA second optional example in a frame of a subframe of 1. In fig. 5, we show SLS allocations for UE RXSS and eNB TXSS, respectively, where PSS 522/532/542 and SLS 528/538/548 are eNB TXSS and SSS 524/534/544 and SLS 526/536/546 are UE RXSS.

In particular, fig. 5 shows a timeline for biasing PSS, SSS, and SLS signals in neighboring cells.

Note that the offset T_offset535 (offset by a factor of 2T for higher numbered cells, for example)_offset545) Is simply applied to the entire frame, which is a simpler arrangement than that shown in figure 4.

3: enhanced downlink control channel for link loss detection

The Physical Downlink Control Channel (PDCCH) occupies the first few symbols of the subframe and therefore can be used by the UE 110 to detect a communication link loss. However, when detecting a communication link loss using only PDCCH, the eNB cannot send PDCCH frequently enough to avoid link loss that is considered detected at UE 110. For example, in the case of sectorization of an eNB, the eNB cannot transmit a PDCCH simultaneously on all its sectors due to the limitation of link budget (i.e., radio resources). In this case, some examples may specify that the eNB may use all of its RF chains together to transmit PDCCH signals on each sector, one sector at a time.

For example, an eNB may have two sectors a and B and two UEs a and B. UE # a may connect to the eNB via sector # a; UE # B may connect to the eNB via sector # B. Here, it may be assumed that the eNB may only transmit PDCCH on sector a or B at a time, but not on both sectors a and B. In this example, if the eNB has a large amount of data traffic for UE # a, the eNB will send PDCCH in consecutive frames on sector # a to schedule traffic for UE # a. Thus, the eNB will not transmit PDCCH on sector # B for a period of time, and therefore the UE may erroneously detect a communication link loss (if it relies solely on the reception of PDCCH).

To provide advantages for this case, a novel downlink broadcast channel (or another control channel, e.g., Beam Reference Signal (BRS)) may be used in accordance with examples of the present disclosure. In the following, it will be referred to as a shortened broadcast channel (sBCH), but any other name may equally be used. After the PDCCH (if it is indeed allocated), sBCH may be allocated to available radio resources such as subframes. The actual allocation of sBCH in time and frequency in a subframe may be configured by (e.g., broadcasted) system information. The length of sBCH may vary, but the maximum value may be fixed (denoted as N) and may be provided to the UE as part of the system information. The sBCH may indicate a cell ID and other resource parameters (e.g., a relative sector index). In sbbch, the relevant eNB may, for example, repeat the transmission of the same symbols on the selected sector. By explaining this process, the following parameters can be defined:

T_sBCH: an sBCH/BRS interval;

k: the number of symbols in the PDCCH;

n: maximum number of symbols of sBCH/BRS;

m: a link loss detection threshold.

Fig. 6 shows how sBCH can be allocated (600) in a subframe with three sectors A, B, and C. In this example, PDCCH 610 is sent on sector # a to schedule traffic for the UE on this sector (i.e., PDCCH is scheduled only for the sector it is using), and sBCH 620 is sent on sectors # B and # C for link loss detection.

sBCH 620 has a value of n-2 because it is transmitted on two sectors in this example. Other values of n may be used and will depend on the number of other sectors involved. At the same time, the corresponding downlink data then follows (640) the PDCCH/sBCH in the usual way. According to the example structure of sBCH of fig. 6, the proposed exemplary PDCCH/sBCH based link loss detection procedure can work as follows:

step 1: if the master eNB # A120 is at the last T_sBCHNo PDCCH or sBCH is sent on a sector in a subframe, the eNB 120 may send a PDCCH on that sector (if nothing prevents it from doing so); otherwise, the eNB 120 may transmit sBCH on the sector after the first k symbols, and the PDCCH (transmitted on a different sector) may also indicate that the first N symbols (N ≦ N) after the PDCCH (i.e., after the end of the PDCCH) are reserved for sBCH.

Step 2: UE 110 receives the first K symbols for PDCCH per subframe from its respective master eNB. If UE 110 does not correctly receive the first K symbols for PDCCH per subframe from its primary eNB, it may continue to receive the next N symbols for sBCH. If UE 110 is at the last mxT_sBCHIf no PDCCH or sBCH has been received from its primary eNB in a subframe, UE 110 may consider its connection to the corresponding primary eNB to be lost.

Master eNB # A120 may broadcast (m, K, N, T) to UE 110_sBCH) As part of the system information.

In some alternative examples, one may be directed to each transmission timeThe inter-interval (TTI) is continuously allocated a new enhanced (cell-specific) reference signal (eRS). eRS, and may be mapped to a sector index, eRS itself may also carry cell ID information. Thus, UE 110 may directly detect the communication link loss through measurement eRS. If the UE gets from its last mx T_eRSWithout eRS received in a subframe, UE 110 may consider its connection to the corresponding master eNB to be lost.

The above is described in an example deployment using enbs with sectors, as this is a more typical arrangement with directional characteristics of mmWave communications. However, the principles of the present disclosure may be equally applied in deployments that do not utilize sectors.

4: persistent scheduling request (pSR) allocation for secondary control links

After UE 110 detects a link loss in its primary cell (i.e., the cell served by eNB # a 120), UE 110 needs to switch to one of its secondary cells (e.g., served by eNB # B130 or # C140) as soon as possible. This may be accomplished using the light-weight scheduling request process now described, in accordance with examples of the present disclosure. The proposed lightweight scheduling request procedure may provide the benefit that UE 110 may maintain Uplink (UL) synchronization with its secondary cell and may also send a request to handover the primary cell via the secondary control link. Similar to LTE, a persistent scheduling request (pSR) for UE 110 in the secondary cell may be persistently assigned. In some examples, the pSR may be transmitted every Transmission Time Interval (TTI), although in other examples, the pSR may be transmitted less regularly, e.g., at intervals of more than one TTI. Changing the granularity of the transmission pSR affects detection time, but less regular transmissions are more radio resource efficient. Thus, the pSR transmission interval may be use case specific.

In addition, a master eNB (e.g., eNB # a 120) of UE 110 may cooperate with its secondary eNB (e.g., eNB # B130) to reconfigure the pSR of UE 110 in the secondary cell. Additionally, in some examples, a novel way of indicating how to allocate psrs may be provided, which may be used for normal subframes or special subframes in which a Downlink (DL) synchronization or broadcast channel (e.g., PSS/SSS/Broadcast Channel (BCH)) occupies the last few symbols of the subframe. According to these examples, the following parameters may be defined:

d_pSR-REQ: a symbol offset between a first symbol of a persistent scheduling request message (i.e., pSR REQ message (UL)) transmitted on an uplink and a last symbol that may be used for DL/UL allocation (excluding PSS/SSS/BCH allocation) in a corresponding subframe;

d_pSR-RSP: a symbol offset between a first symbol of the pSR REQ message (UL) and a first symbol of the pSR RSP message (DL);

T_pSR: the cycle time (in slots/subframes) of the persistent scheduling request, i.e. the frequency of transmission of the persistent scheduling request in a subframe, may be, for example, every subframe (which is very sensitive to link loss but not radio resource efficient), or it may be every x subframes (e.g. 10 subframes, which uses the available radio resources more efficiently but with a loss of sensitivity to link loss).

FIG. 7 shows how the pSR-REQ message and the pSR-RSP message may be allocated in a subframe, e.g., around PDCCH, PSS/SSS/BCH, etc., of a special subframe; fig. 8 shows how the pSR-REQ message and the pSR-RSP message may be allocated in a normal subframe. The essential point of these figures is that it is shown according to the parameter d _pSR-REQ 730、d _pSR-RSP740. And T_pSRScheduling a persistent scheduling request (pSR) at a set persistent location in a corresponding subframe. Notably, persistent scheduling seeks to place the pSR at a point directed by the last symbol that can be used for UE-specific resource allocation, which may be from the end of the corresponding subframe (e.g., normal subframe) or from the last N +1 th symbol of the subframe (if the last N symbols are used for PSS, SSS, BCH, SLS, or any other signal (e.g., special subframe)). In any case, the master eNB (e.g., eNB # a 120) of UE 110 may cooperate with the secondary eNB(s) (e.g., eNB # B130 or # C140) to reconfigure the pSR (d) of the UE_pSR-REQ、d_pSR-RSP、 T_pSR)。

5: fast Cell Switching (FCS) procedure

Fig. 9 illustrates a high-level flow diagram of a method 900 of detecting a loss of a communication link according to an example.

Prior to this approach, the respective primary eNB sends the sBCH broadcast parameters discussed above to the UE, e.g., in system information (905).

In step 910, the UE may attempt to detect whether its primary communication link(s) (or at least one of the primary communication links) with the primary eNB is lost (i.e., blocked) by using PDCCH, sBCH, or eRS signals, as discussed in detail above. Specifically, the loss of the communication link may be determined by incorrect or non-reception of the corresponding control signal (PDCCH, sBCH, or eRS). If a loss of communication link occurs, the result of the "correct reception test" is negative (925), the method proceeds to step 930, the corresponding primary communication link is determined to be lost in step 930, and a fast handover cell procedure is instigated, for example, as discussed in detail below with respect to fig. 10.

If the test result of "correctly received test" is positive (915), then the backbone is trouble free (920) and can continue to be used. Test 910 may then be repeated. Fig. 10 shows in more detail some key steps in a method 1000 for a UE 110 to handover its primary cell according to an FCS procedure, according to some example embodiments. In the example of fig. 10, it is assumed that the UE 110 is connected to one anchor eNB (# a)120 (i.e., the current master eNB) and two booster enbs (eNB # B130 and eNB # C140), where eNB # B130 is the current first secondary eNB, eNB # C140 is the current second secondary eNB, and the secondary eNB to be used as the master eNB is eNB # B130.

At the very beginning, the anchor eNB (# a)120 is the master eNB, and the booster eNB (# B)130 is the slave eNB. UE 110 is configured with periodic pSR 1010 from eNB # B130 so that UE 110 can maintain UL synchronization in the secondary cell while transmitting data in the primary cell. The UE transmits data in the primary cell using a communication link provided to the UE by the primary cell eNB. The period of the periodic pSR is defined by the parameter T_pSRAnd (4) setting.

During use of the primary communication link, PDCCH/sBCH/eRS are transmitted 1020 by primary eNB # a120 and received correctly by UE 110 while they are still operating normally (i.e., not considered lost or broken). That is, UE 110 continues to receive PDCCH, sBCH, or eRS from its primary eNB (# a)120 and pSR from secondary eNB (# B) 130.

However, when UE 110 fails to properly receive any one or more of PDCCH, sBCH, or eRS, the primary communication link between the UE and the primary eNB is considered lost or broken, as discussed above. 1020 for the second and third PDCCH/sBCH/eRS transmissions, which are shown by cross 1025. This may be in the region of m x T_sBCHAs shown and discussed in detail above, in a defined time frame. When UE 110 detects a communication link loss, it may trigger FCS procedure 1040 (see section 3 above for more details).

At the same time, UE 110 continues to receive pSR signals from the secondary cell eNB, but may only request transfer of data transmitted on the (now lost) primary communication link to the active "hot swap" secondary communication link provided by the secondary eNB (e.g., eNB # B130) at the next allocated pSR transmission.

Once the FCS procedure 1040 is triggered, the UE 110 selects one of its secondary enbs (in this case eNB # B130 as described above) as its new master eNB based on, for example, the received channel strength or other measurements, and proceeds to step 4.

Thus, at 1050, UE 110 may send an FCS REQ message (e.g., as part of pSR-REQ) to the selected secondary eNB (eNB # B130).

At 1060, the selected eNB (eNB # B130) will respond to the FCS REQ message received from the UE 110 with an FCS RSP message (e.g., as part of pSR-RSP), confirming the handover.

The old secondary eNB # B130 is now the new master eNB. Thus, wireless UE-eNB interface traffic/data (i.e., traffic/data to be transmitted between the respective UE and the wireless network (i.e., eNB)) will now be transmitted to the new master eNB, and in the event that the new master eNB is not an anchor eNB, it may be routed to the core network via the anchor eNB.

Next, at 1070, the new master eNB (eNB # B130) will send an FCS notification message to the anchor eNB (eNB # a 120) so that it can update its information and start forwarding DL traffic to the new master eNB (eNB # B130), e.g., via the X2 interface.

At 1080, the new master eNB (eNB # B130) may initiate a sector selection procedure so that the UE 110 may select the most appropriate sector of eNB # B130 for data transmission in the new master cell.

It will be appreciated that in some examples, only a single secondary eNB may be included or more than two secondary enbs may be included. In the former case, the selection is simpler, i.e., the system selects only "another"; in the latter case, there may be an appropriate selection method to select the best secondary eNB as the master eNB. The present disclosure is not limited in this respect. Examples of selection methods may include, but are not limited to, cell capacity, cell signal quality, cell signal strength, cell distance, cell frequency, and the like.

Fig. 11 illustrates an eNB and a UE in accordance with some embodiments of the present disclosure. Fig. 11 includes a block diagram of an eNB 1110 and a UE 1130 that are operable to coexist with each other and other elements of an LTE network. A high-level simplified architecture of the eNB 1110 and the UE 1130 is described to avoid obscuring embodiments. It should be noted that in some embodiments, eNB 1110 may be a stationary non-mobile device.

The eNB 1110 is coupled to one or more antennas 1105 and the UE 1130 is similarly coupled to one or more antennas 1125. However, in some embodiments, eNB 1110 may incorporate or include antenna 1105, and in various embodiments UE 1130 may incorporate or include antenna 1125.

In some embodiments, antenna 1105 and/or antenna 1125 may include one or more directional or omnidirectional antennas, including monopole antennas, dipole antennas, loop antennas, patch antennas, microstrip antennas, coplanar wave antennas, or other types of antennas suitable for transmission of RF signals. In some MIMO (multiple input multiple output) embodiments, the antennas 1105 are separated to exploit spatial diversity.

The eNB 1110 and the UE 1130 are operable to communicate with each other over a network, e.g., a wireless network. The eNB 1110 and the UE 1130 may communicate with each other over a wireless communication channel 1150, where the wireless communication channel 1150 has a downlink path from the eNB to the UE 1130 and an uplink path from the UE 1130 to the eNB 1110.

As shown in fig. 11, in some embodiments, eNB 1110 may include physical layer circuitry 1112, MAC (medium access control) circuitry 1114, a processor 1116, a memory 1118, and hardware processing circuitry 1120. Those skilled in the art will appreciate that other components not shown in the figures may be used in addition to those shown in the figures to form a complete eNB.

In some embodiments, the physical layer circuitry 1112 includes a transceiver 1113 for providing signals to and from the UE 1130. The transceiver 1113 provides signals to and from the UE or other devices using the one or more antennas 1105. In some embodiments, MAC circuitry 1114 controls access to the wireless medium. The memory 1118 may be or include a storage medium/media such as a magnetic storage medium (e.g., a tape or disk), an optical storage medium (e.g., an optical disk), an electronic storage medium (e.g., a conventional hard disk drive, a solid state drive, or a flash memory-based storage medium), or any tangible or non-transitory storage medium. Hardware processing circuit 1120 may comprise logic devices or circuits that perform various operations. In some embodiments, the processor 1116 and the memory 1118 are arranged to perform operations of the hardware processing circuitry 1120, e.g., the operations described herein for the logic devices and circuitry in the eNB 1110 and/or the hardware processing circuitry 1120. Accordingly, in some embodiments, eNB 1110 may be a device that includes an application processor, memory, one or more antenna ports, and an interface to allow the application processor to communicate with another device.

Additionally, as shown in fig. 11, in some embodiments, the UE 1130 may include physical layer circuitry 1132, MAC circuitry 1134, a processor 1136, a memory 1138, hardware processing circuitry 1140, a wireless interface 1142, and a display 1144. It will be apparent to those skilled in the art that other components not shown in the figures may be used in addition to those shown in the figures to form a complete UE.

In some embodiments, the physical layer circuitry 1132 includes a transceiver 1133 for providing signals to and from the eNB 1110 (and other enbs). The transceiver 1133 provides signals to and from an eNB or other device using one or more antennas 1125. In some embodiments, the MAC circuitry 1134 controls access to the wireless medium. The memory 1138 may be or include a storage medium/media such as a magnetic storage medium (e.g., tape or disk), an optical storage medium (e.g., optical disk), an electronic storage medium (e.g., a conventional hard disk drive, solid state drive, or flash memory-based storage medium), or any tangible or non-transitory storage medium. The wireless interface 1142 may be arranged to allow the processor to communicate with another device. The display 1144 may provide a visual and/or tactile display, such as a touch screen display, for a user to interact with the UE 1130. Hardware processing circuit 1140 may comprise logic devices or circuitry that perform various operations. In some embodiments, the processor 1136 and memory 1138 may be arranged to perform operations of the hardware processing circuitry 1140, e.g., operations described herein for logic devices and circuitry in the UE 1130 and/or hardware processing circuitry 1140.

Accordingly, in some embodiments, the UE 1130 may be a device that includes an application processor, memory, one or more antennas, a wireless interface to allow the application processor to communicate with another device, and a touchscreen display. The elements of fig. 11 and elements of other figures having the same name or reference number may operate or function in the manner described herein with respect to any of these figures (although the operation and function of these elements is not limited to these descriptions).

In addition, although the eNB 1110 and the UE 1130 are each described as having several separate functional elements, one or more of the functional elements may be combined together and may be implemented by a combination of software-configured elements and/or other hardware elements. In some embodiments of the present disclosure, a functional element may refer to one or more processes running on one or more processing elements. Examples of software and/or hardware configuration elements include a Digital Signal Processor (DSP), one or more microprocessors, a DSP, a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), a Radio Frequency Integrated Circuit (RFIC), and so forth.

The eNB may include various hardware processing circuitry discussed herein, which in turn may include logic devices and/or circuitry operable to perform various operations. For example, referring to fig. 11, eNB 1110 (or various elements or components herein, e.g., hardware processing circuitry 1120, or a combination of elements or components herein) may include some or all of these hardware processing circuitry.

In some embodiments, one or more of these hardware processing circuits or circuits may be implemented by a combination of software-configured elements and/or other hardware elements. For example, the processor 1116 of the eNB 1110 (which may include the hardware processing circuitry 1120) (and/or one or more other processors that the eNB 1110 may include), the memory 118, and/or other elements or components may be arranged to perform operations of these hardware processing circuitry, e.g., the operations described herein for the devices and circuitry therein. In some embodiments, processor 1116 (and/or one or more other processors that eNB 1110 may include) may be a baseband processor.

Similarly, the UE may include various hardware processing circuitry discussed herein, which may include logic devices and/or circuitry operable to perform various operations. For example, referring to fig. 11, the UE 1130 (or various elements or components herein, e.g., the hardware processing circuitry 1140, or a combination of elements or components herein) may include some or all of these hardware processing circuitry. In some embodiments, one or more of these hardware processing circuits or circuits may be implemented by a combination of software-configured elements and/or other hardware elements. For example, the processor 1136 of the UE 1130 (which may include the hardware processing circuitry 1140) (and/or one or more other processors that the UE 1130 may include), the memory 1138, and/or other elements or components may be arranged to perform operations of these hardware processing circuitry, e.g., the operations described herein for the devices and circuitry therein. In some embodiments, processor 1136 (and/or one or more other processors that UE 1130 may include) may be a baseband processor.

Various methods described herein may involve the eNB 1110 and the hardware processing circuitry 1120. Although the acts in the methods described herein are shown in a particular order, the order of the acts may be modified. Thus, the illustrated embodiments may be performed in a different order, and some actions may be performed in parallel. Some actions and/or operations recited may be optional in accordance with certain embodiments. The numbering of the acts is presented for the sake of clarity and is not intended to dictate the order in which the various acts must be performed. In addition, operations from various streams may be used in various combinations. Additionally, in some embodiments, a machine-readable storage medium may have executable instructions that, when executed, cause the eNB 1110 and/or the hardware processing circuitry 1120 to perform operations comprising any of the methods described. Such machine-readable storage media may include any of a variety of storage media such as magnetic storage media (e.g., tape or disk), optical storage media (e.g., optical disk), electronic storage media (e.g., a conventional hard disk drive, solid state drive, or flash memory-based storage media), or any other tangible or non-transitory storage media. In some embodiments, an apparatus may comprise means for performing various acts and/or operations of the methods.

Similarly, various methods are also described herein that may involve the UE 1130 and the hardware processing circuitry 1140. Additionally, while the actions may be shown in a particular order, the order of the actions may be modified. Thus, the illustrated embodiments may be performed in a different order, and some actions may be performed in parallel. Some actions and/or operations performed by the UE are optional according to certain embodiments. The numbering of the acts is presented for the sake of clarity and is not intended to dictate the order in which the various acts must be performed. In addition, operations from various streams may be used in various combinations.

Additionally, in some embodiments, a machine-readable storage medium may have executable instructions that, when executed, cause the UE 1130 and/or the hardware processing circuitry 1140 to perform operations comprising any of the disclosed methods. Such machine-readable storage media may include any of a variety of storage media such as magnetic storage media (e.g., tape or disk), optical storage media (e.g., optical disk), electronic storage media (e.g., a conventional hard disk drive, solid state drive, or flash memory-based storage media), or any other tangible or non-transitory storage media.

The embodiments described herein may be implemented in a system using any suitably configured hardware and/or software. FIG. 12 illustrates example components of an electronic device 1200 of an embodiment. In embodiments, electronic device 1200 may be implemented as or incorporated into or as part of a User Equipment (UE), an evolved node b (enb), or another network component (e.g., a network component corresponding to a network virtualization device and/or a software-defined network device). In some embodiments, the electronic device 1200 may include application circuitry 1210, baseband circuitry 1220, Radio Frequency (RF) circuitry 1230, Front End Module (FEM) circuitry 1240, and one or more antennas 1250 coupled together at least as shown.

The application circuitry 1210 may include one or more application processors. For example, the application circuitry 1210 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The one or more processors may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors, application processors, etc.). The processor may be coupled to and/or include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.

The baseband circuitry 1220 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. Baseband circuitry 1220 may include one or more baseband processors and/or control logic to process baseband signals received from the receive signal path of RF circuitry 1230 and to generate baseband signals for the transmit signal path of RF circuitry 1230. The baseband processing circuitry 1220 may interface with the application circuitry 1210 for generating and processing baseband signals and for controlling the operation of the RF circuitry 1230. For example, in some embodiments, the baseband circuitry 1220 may include a second generation (2G) baseband processor 1221, a third generation (3G) baseband processor 1222, a fourth generation (4G) baseband processor 1223, and/or other baseband processors 1224 for other existing generations, generations under development or later developed (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 1220 (e.g., one or more baseband processors 1221 and 1224) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 1230. Radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, and the like. In some embodiments, the modulation/demodulation circuitry of the baseband circuitry 1220 may include Fast Fourier Transform (FFT), precoding, and/or constellation mapping/demapping functionality. In some embodiments, the encoding/decoding circuitry of baseband circuitry 1220 may include convolution, tail-biting convolution, turbo, Viterbi, and/or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functions are not limited to these examples, and other suitable functions may be included in other embodiments.

In some embodiments, baseband circuitry 1220 may include elements of a protocol stack, such as an Evolved Universal Terrestrial Radio Access Network (EUTRAN) protocol, including, for example, a Physical (PHY), a Medium Access Control (MAC), a Radio Link Control (RLC), a Packet Data Convergence Protocol (PDCP) element, a Radio Resource Control (RRC) element, and/or the disclosed MCCP layer protocols. A Central Processing Unit (CPU)1225 of the baseband circuitry 1220 may be configured to run elements of a protocol stack for signaling of PHY, MAC, RLC, PDCP, RRC, and/or MCCP layers. In some embodiments, the baseband circuitry may include one or more audio Digital Signal Processors (DSPs) 1226. The audio DSP 1226 may include elements for compression/decompression and echo cancellation, and may include other suitable processing elements in other embodiments.

The baseband circuitry 1220 may also include memory/storage 1227. The memory/storage device 1227 may be used to load and store data and/or instructions for operations performed by the processor of the baseband circuitry 1220. The memory/storage devices of one embodiment may comprise any combination of suitable volatile memory and/or non-volatile memory. Memory/storage 1227 may include any combination of various levels of memory/storage including, but not limited to, Read Only Memory (ROM) embedded with software instructions (e.g., firmware), random access memory (e.g., Dynamic Random Access Memory (DRAM)), cache, buffers, and the like. The memory/storage 1227 may be shared among the various processors or dedicated to a particular processor.

In some embodiments, the components of the baseband circuitry may be combined in a single chip or single chipset, as appropriate, or may be placed on the same circuit board. In some embodiments, some or all of the constituent components of the baseband circuitry 1220 and the application circuitry 1210 may be implemented together, for example, on a system on a chip (SOC).

In some embodiments, the baseband circuitry 1220 may provide communications compatible with one or more radio technologies. For example, in some embodiments, baseband circuitry 1220 may support communication with an Evolved Universal Terrestrial Radio Access Network (EUTRAN) and/or other Wireless Metropolitan Area Networks (WMANs), Wireless Local Area Networks (WLANs), Wireless Personal Area Networks (WPANs). Embodiments in which the baseband circuitry 1220 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

RF circuitry 1230 may enable communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, RF circuitry 1230 may include switches, filters, amplifiers, and the like to facilitate communication with a wireless network. The RF circuitry 1230 may include a receive signal path that may include circuitry to down-convert RF signals received from the FEM circuitry 1240 and provide baseband signals to the baseband circuitry 1220. RF circuitry 1230 may also include a transmit signal path, which may include circuitry to up-convert baseband signals provided by baseband circuitry 1220 and provide RF output signals to FEM circuitry 1240 for transmission.

In some embodiments, RF circuitry 1230 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 1230 may include mixer circuitry 1231, amplifier circuitry 1232, and filter circuitry 1233. The transmit signal path of the RF circuitry 1230 may include filter circuitry 1233 and mixer circuitry 1231. The RF circuitry 1230 may also include synthesizer circuitry 1234 for synthesizing frequencies for use by the mixer circuitry 1231 of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 1231 of the receive signal path may be configured to down-convert the RF signal received from the FEM circuitry 1240 based on the synthesized frequency provided by the synthesizer circuitry 1234. The amplifier circuit 1232 may be configured to amplify the downconverted signal, and the filter circuit 1233 may be a Low Pass Filter (LPF) or a Band Pass Filter (BPF) configured to remove unwanted signals from the downconverted signal to generate an output baseband signal. The output baseband signal may be provided to baseband circuitry 1220 for further processing. In some embodiments, the output baseband signal may be a zero frequency baseband signal, although this is not required. In some embodiments, mixer circuit 1231 of the receive signal path may comprise a passive mixer, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry 1231 of the transmit signal path may be configured to up-convert the input baseband signal based on the synthesis frequency provided by the synthesizer circuitry 1232 to generate the RF output signal for the FEM circuitry 1240. The baseband signal may be provided by the baseband circuitry 1220 and may be filtered by the filter circuitry 1233. Filter circuitry 1233 may include a Low Pass Filter (LPF), although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry 1231 of the receive signal path and the mixer circuitry 1231 of the transmit signal path may comprise two or more mixers and may be arranged for quadrature down-conversion and/or up-conversion, respectively. In some embodiments, the mixer circuit 1231 of the receive signal path and the mixer circuit 1231 of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., hartley image rejection). In some embodiments, the mixer circuit 1231 and the mixer circuit 1231 of the receive signal path may be arranged for direct down-conversion and/or direct up-conversion, respectively. In some embodiments, the mixer circuitry 1231 of the receive signal path and the mixer circuitry 1231 of the transmit signal path may be configured for superheterodyne operation.

In some embodiments, the output baseband signal and the input baseband signal may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternative embodiments, the output baseband signal and the input baseband signal may be digital baseband signals. In these alternative embodiments, RF circuitry 1230 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and baseband circuitry 1220 may include a digital baseband interface to communicate with RF circuitry 1230.

In some dual-mode embodiments, separate radio IC circuits may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect.

In some embodiments, synthesizer circuit 1234 may be a fractional-N synthesizer or a fractional-N/N +1 synthesizer, although the scope of the embodiments is not limited in this respect and other types of frequency synthesizers may also be suitable. For example, synthesizer circuit 1234 may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer that includes a phase locked loop with a frequency divider.

The synthesizer circuit 1234 may be configured to synthesize an output frequency for use by the mixer circuit 1231 of the RF circuit 1230 based on the frequency input and the divider control input. In some embodiments, synthesizer circuit 1234 may be a fractional-N/N +1 synthesizer.

In some embodiments, the frequency input may be provided by a Voltage Controlled Oscillator (VCO), although this is not required. The divider control input may be provided by the baseband circuitry 1220 or the applications processor 1210 depending on the desired output frequency. In some embodiments, the divider control input (e.g., N) may be determined from a look-up table based on the channel indicated by the application processor 1210.

Synthesizer circuit 1234 of RF circuit 1230 may include frequency dividers, Delay Locked Loops (DLLs), multiplexers, and phase accumulators. In some embodiments, the frequency divider may be a dual-mode frequency divider (DMD) and the phase accumulator may be a Digital Phase Accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by N or N +1 (e.g., based on a carry) to provide a fractional division ratio. In some example embodiments, a DLL may include a set of cascaded, tunable delay elements, a phase detector, a charge pump, and a D-type flip-flop. In these embodiments, the delay elements may be configured to divide the VCO period into Nd equal phase packets, where Nd is the number of delay elements in the delay line. Thus, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

In some embodiments, the synthesizer circuit 1234 may be configured to generate a carrier frequency as the output frequency, but in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and may be used in conjunction with a quadrature generator and divider circuit to generate multiple signals at the carrier frequency having multiple phases that are different from one another. In some embodiments, the output frequency may be the LO frequency (f)_LO). In some embodiments, RF circuitry 1230 may include an IQ/polarity converter.

FEM circuitry 1240 may include a receive signal path that may include circuitry configured to operate on RF signals received from one or more antennas 1250, amplify the received signals, and provide amplified versions of the received signals to RF circuitry 1230 for further processing. The FEM circuitry 1240 may also include a transmit signal path, which may include circuitry configured to amplify one or more of the antennas 1250 provided by the RF circuitry 1230 for transmission.

In some embodiments, FEM circuitry 1240 may include a TX/RX switch to switch between transmit mode operation and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a Low Noise Amplifier (LNA) to amplify the receive RF signal and provide the amplified receive RF signal as an output (e.g., to RF circuitry 1230). The transmit signal path of the FEM circuitry 1240 may include a Power Amplifier (PA) that amplifies an input RF signal (e.g., provided by the RF circuitry 1230), and one or more filters that generate the RF signal for subsequent transmission (e.g., one or more of the one or more antennas 1250).

In various embodiments, Network Interface Controller (NIC) circuitry 1260 may include one or more transmit and receive (TX/RX) signal paths, which may be connected to one or more data packet networks via network interface circuitry 1265. In some embodiments, NIC circuit 1260 may be coupled to a data packet network via a plurality of network interface circuits 1265. NIC circuit 1260 may support one or more data link layer standards such as ethernet, fiber, token ring, Asynchronous Transfer Mode (ATM), and/or any other suitable data link layer standard. In some embodiments, each network element (e.g., base station, network controller, Radio Access Network (RAN) device, S-GW, SDN switch, MME, P-GW, etc.) to which electronic device 1200 may connect may include the same or similar network interface circuitry 1265. Additionally, NIC circuit 1260 may include or may be associated with processing circuitry, such as one or more single-core or multi-core processors and/or logic circuits, to provide processing techniques suitable for communicating in accordance with one or more data link layer standards utilized by the NIC circuit.

In some embodiments, electronic device 1200 may include additional elements such as memory/storage devices, displays, cameras, sensors, and/or input/output (I/O) interfaces.

In some embodiments, the electronic device of fig. 12 may be configured to perform one or more of the processes, techniques, and/or methods described herein, or portions thereof.

Fig. 13 is a block diagram illustrating components capable of reading instructions from a machine-readable or computer-readable medium (e.g., a machine-readable storage medium) and performing any one or more of the methodologies discussed herein, according to some example embodiments. In particular, fig. 13 shows a pictorial representation of hardware resources 1300 including one or more processors (or processor cores) 1310, one or more memory/storage devices 1320, and one or more communication resources 1330 that are communicatively coupled via a bus 1340.

Processor 1310 (e.g., a Central Processing Unit (CPU), a Reduced Instruction Set Computing (RISC) processor, a Complex Instruction Set Computing (CISC) processor, a Graphics Processing Unit (GPU), a Digital Signal Processor (DSP) such as a baseband processor, an Application Specific Integrated Circuit (ASIC), a Radio Frequency Integrated Circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, processor 1312 and processor 1314. The memory/storage 1320 may include a main memory, a disk storage device, or any suitable combination thereof.

Communication resources 1330 can include interconnection and/or network interface components or other suitable devices to communicate with one or more peripherals 1304 and/or one or more databases 1306 via network 1308. For example, communication resources 1330 can include a wired communication component (e.g., for coupling via a Universal Serial Bus (USB)), a cellular communication component, a Near Field Communication (NFC) component, a wireless communication component, and/or a wireless communication component,

The components (e.g.,

low energy),

Components, and other communication components.

The instructions 1350 may include software, programs, applications, applets, applications, or other executable code for causing at least any one of the processors 1310 to perform one or more of the methods discussed herein. The instructions 1350 may reside, completely or partially, within at least one of the processor 1310 (e.g., within a cache memory of the processor), the memory/storage 1320, or any suitable combination thereof. Additionally, any portion of instructions 1350 may be transmitted to hardware resource 1300 from any combination of peripherals 1304 and/or database 1306. Accordingly, the memory of processor 1310, memory/storage 1320, peripherals 1304, and database 1306 are examples of computer-readable media and machine-readable media.

Although the above examples may be used in the context of a 5G RAT for licensed bands, the principles covered are general and readily applied to alternative designs. For example, examples of the present disclosure may be applied to alternative mmWave access systems such as WiGig/802.11ay or potentially to any other large multiple-input multiple-output (MIMO) system, and in particular to systems that utilize directional acquisition/arbitrary signals (control or data) of a directional nature.

Similarly, although the above examples are the best examples described in the context of a particular frame structure, the relevant principles have general applicability and may be applied to alternative frame structures or multiple access mechanisms.

According to the examples described herein, a novel c-plane/u-plane protocol stack and multi-connectivity network architecture are provided that are operable to support an efficient "hot-standby" configuration between a primary cell and a secondary cell, wherein the "hot-standby" configuration allows for fast transfer of control traffic and data traffic between cells when a communication link of a primary (i.e., primary) communication link is lost.

According to the examples described herein, a novel inter-cell coordination method for synchronizing PSS/SSS/SLS is provided.

According to examples described herein, a novel broadcast channel (e.g., shortened BCH) or enhanced reference signal (eRS) for fast communication link loss detection is provided. Specific examples may utilize more than one new type of broadcast channel or reference signal, even utilizing the PDCCH to detect communication link loss. According to examples described herein, a new method of supporting persistent allocation of scheduling requests in subframes (i.e., normal subframes or special subframes) with or without PSS/SSS/SLS/BCH is provided.

According to the examples described herein, a novel SR (scheduling request) based fast cell handover (FCS) procedure/protocol is provided.

Examples of the present disclosure may be used in future 3GPP standards (R14 and beyond).

Reference in the specification to "an embodiment," "one embodiment," "some embodiments," or "other embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments. Various appearances of "an embodiment," "one embodiment," or "some embodiments" are not necessarily all referring to the same embodiments. If the specification states a component, feature, structure, or characteristic "may", "might", or "could" be included, that particular component, feature, structure, or characteristic is not required to be included. If the specification or claim refers to "a" or "an" element, that does not mean there is only one of the element. If the specification or claims refer to "an additional" element, that does not preclude there being more than one of the additional element.

Furthermore, the particular features, structures, functions, or characteristics may be combined in any suitable manner in one or more embodiments. For example, the first embodiment may be combined with the second embodiment, wherein particular features, structures, functions, or characteristics associated with the two embodiments are not mutually exclusive.

While the present disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations to those embodiments will be apparent to those skilled in the art in light of the foregoing description. For example, other memory architectures, such as dynamic ram (dram), may use the embodiments discussed. The embodiments of the present disclosure are intended to embrace all such alternatives, modifications and variances that fall within the broad scope of the appended claims.

In addition, well known power/ground connections to Integrated Circuit (IC) chips and other components may or may not be shown within the presented figures for simplicity of illustration and discussion, and so as not to obscure the disclosure. Additionally, such block diagrams may be shown in block diagram form in order to avoid obscuring the disclosure and in view of the fact that specifics with respect to implementation of such block diagram arrangements are highly dependent upon the platform within which the present disclosure is to be implemented (i.e., such specifics should be well within purview of one skilled in the art). Where specific details (e.g., circuits) are provided to describe example embodiments of the disclosure, it will be apparent to one skilled in the art that the disclosure may be practiced without, or with variation of, these specific details. The description is to be regarded as illustrative instead of limiting.

The following examples relate to further embodiments. The specific details in the examples may be used anywhere in one or more embodiments. All optional features of the apparatus described herein may also be implemented with respect to the method or process.

Example 1 may include an apparatus of a User Equipment (UE) operable to communicate with an evolved node b (enb) on a wireless network, comprising: one or more processors configured to: maintaining a plurality of radio access network communication links between the UE and at least two enbs of a radio access network of the wireless network, wherein at least a first eNB is an anchor eNB and wherein at least a second eNB is a booster eNB, the plurality of radio access network communication links between the UE and the radio access network of the wireless network including at least one primary communication link and at least one secondary communication link; and when it is determined that the at least one primary communication link is lost, switching from actively transmitting and receiving data of the UE using the at least one primary communication link to actively transmitting and receiving data of the UE using the at least one secondary communication link; wherein the anchoring eNB is operable to provide communication between the UE and a core network of the serving wireless network and communication between the UE and a radio access network providing the wireless network; and wherein the booster eNB is operable to provide communication between the UE and a radio access network providing the wireless network, and is operable to communicate with the core network only via the anchor eNB.

Example 2 may include the apparatus of example 1 or any other example herein, wherein the anchor eNB provides user-plane and control-plane communications between the UE and the core network.

Example 3 may include the apparatus of example 1 or 2 or any other example herein, wherein the booster eNB provides user plane and control plane communications between the UE and the anchor eNB. Another example may include the apparatus of any other example, wherein the booster eNB provides user plane and control plane communications between the UE and the core network.

Example 4 may include the apparatus of any one of examples 1 to 3 or any other example herein, wherein the booster eNB is in communication with the anchor eNB over an eNB-to-eNB communication link interface, optionally over an X2 interface.

Example 5 may include the apparatus of any one of examples 1 to 4 or any other example herein, wherein the UE maintains at least two primary communication links, and wherein the one or more processors are further to divide traffic to be transmitted between the at least two primary communication links.

Example 6 may include the apparatus of example 5 or any other example herein, wherein dividing traffic to be transmitted between at least two primary communication links comprises providing at least two bearer links, wherein a bearer link is assigned to each primary communication link.

Example 7 may include the apparatus of any one of examples 1 to 6 or any other example herein, wherein the one or more processors are further to: a multi-connectivity convergence protocol (MCCP) stack entity is provided, wherein the MCCP stack entity operates above respective radio access network protocol sub-stacks, and wherein the MCCP stack entity manages how UE data traffic is routed over the primary and secondary communication links.

Example 8 may include the apparatus of any one of examples 1 to 7 or any other example herein, wherein operating above the respective radio access network protocol sub-stacks comprises operating above a Packet Data Convergence Protocol (PDCP) stack entity of each wireless communication link operating in the UE.

Example 9 may include the apparatus of any one of examples 1 to 8 or any other example herein, wherein each wireless communication link in the UE comprises separate user plane and control plane stacks to provide operation independent of each other wireless communication link operating in the UE.

Example 10 may include the apparatus of any one of examples 1 to 9 or any other example herein, wherein the one or more processors are further to provide PDCP bearer splitting by the MCCP stack entity.

Example 11 may include the apparatus of any one of examples 7 to 10 or any other example herein, wherein the MCCP stack entity comprises a user plane part MCCP-u and a control plane part MCCP-c.

Example 12 may include a UE device comprising the apparatus of any of examples 1 to 11, the UE device comprising an application processor, a memory, one or more antennas, a wireless interface to allow the application processor to communicate with another device, and a touchscreen display.

Example 13 may include a machine-readable storage medium having machine-executable instructions that, when executed, cause one or more processors to perform operations in a User Equipment (UE) operable to communicate with an evolved node b (enb) over a wireless network, the operations comprising: maintaining a plurality of radio access network communication links between the UE and at least two enbs of a radio access network of the wireless network, wherein at least a first eNB is an anchor eNB and wherein at least a second eNB is a booster eNB, the plurality of radio access network communication links between the UE and the radio access network of the wireless network including at least one primary communication link and at least one secondary communication link; and when it is determined that the at least one primary communication link is lost, switching from actively transmitting and receiving data of the UE using the at least one primary communication link to actively transmitting and receiving data of the UE using the at least one secondary communication link.

Example 14 may include the machine-readable storage medium of example 13 or any other example herein, further comprising: maintaining at least two primary communication links; and dividing traffic to be transmitted between the at least two primary communication links.

Example 15 may include the machine-readable storage medium of example 13 or 14 or any other example herein, further comprising: at least two bearer links are provided, wherein a bearer link is assigned to each primary communication link.

Example 16 may include the machine-readable storage medium of any one of examples 13 to 15 or any other example herein, further comprising: providing a multi-connectivity convergence protocol (MCCP) stack entity operating above respective radio access network protocol sub-stacks; and using the MCCP stack entity to manage how to route UE data traffic over the primary and secondary communication links.

Example 17 may include the machine-readable storage medium of example 16 or any other example herein, wherein operating above the respective radio access network protocol sub-stacks comprises operating above a Packet Data Convergence Protocol (PDCP) stack entity of each wireless communication link provided in the UE.

Example 18 may include the machine-readable storage medium of any one of examples 13 to 17 or any other example herein, further comprising: separate user plane and control plane stacks are provided for each separate wireless communication link provided in the UE.

Example 19 may include the machine-readable storage medium of any one of examples 13 to 18 or any other example herein, further comprising: PDCP bearer partitioning is provided by an MCCP stack entity.

Example 20 may include the machine-readable storage medium of any one of examples 16 to 18, wherein the MCCP stack entity comprises a user plane part MCCP-u and a control plane part MCCP-c.

Example 21 may include a method in a User Equipment (UE) operable to communicate with an evolved node b (enb) on a wireless network, comprising: connect and communicate with at least two eNBs, wherein at least a first eNB is an anchor eNB, and wherein at least a second eNB is a booster eNB; maintaining a plurality of radio access network communication links between the UE and a radio access network of the wireless network, the plurality of radio access network communication links between the UE and the radio access network of the wireless network including at least one primary communication link and at least one secondary communication link; when it is determined that the at least one primary communication link is lost, switching from actively transmitting and receiving data for the UE using the at least one primary communication link to actively transmitting and receiving data for the UE using the at least one secondary communication link.

Example 22 may include the method of example 21 or any other example herein, further comprising: maintaining at least two primary communication links; and dividing traffic to be transmitted between the at least two primary communication links.

Example 23 may include the method of example 21 or 22 or any other example herein, further comprising: at least two bearer links are provided, wherein a bearer link is assigned to each primary communication link.

Example 24 may include the method of any one of examples 21 to 23 or any other example herein, further comprising: providing a multi-connectivity convergence protocol (MCCP) stack entity operating above respective radio access network protocol sub-stacks; and using the MCCP stack entity to manage how to route UE data traffic over the primary and secondary communication links.

Example 25 may include the method of example 24 or any other example herein, wherein operating above the respective radio access network protocol sub-stacks comprises operating above a Packet Data Convergence Protocol (PDCP) stack entity of each wireless communication link provided in the UE.

Example 26 may include the method of any one of examples 21 to 25 or any other example herein, further comprising: separate user plane and control plane stacks are provided for each separate wireless communication link provided in the UE.

Example 27 may include the method of any one of examples 21 to 26 or any other example herein, further comprising: PDCP bearer partitioning is provided by an MCCP stack entity.

Example 28 may include the method of any one of examples 24 to 27 or any other example herein, wherein the MCCP stack entity comprises a user plane part MCCP-u and a control plane part MCCP-c.

Example 29 may provide an apparatus of a skilled node b (enb) operable to communicate with a User Equipment (UE) on a wireless network, comprising: one or more processors configured to: selectively operating the eNB in a first operational state to act as an anchor eNB for the at least one UE, wherein operating as the anchor eNB includes providing communication between the at least one UE and a core network of a serving wireless network; and selectively operating the eNB to act as a booster eNB for the at least one UE in the second operational state, wherein operating as the booster eNB includes providing communication between the at least one UE and a radio access network of the wireless network; wherein the one or more processors are further to: selecting between the first and second operating states based on information from the at least one UE.

Another example may include the eNB of example 29 or any other example herein, wherein selecting between the first and second operating states based on the information from the at least one UE may include any one or more of: based on specific data or specific signals received from the UE (e.g., based on data or signals sBCH, eRS, PDCCH from system information); based on receiving or processing specific data or specific signals from the UE (e.g., based on receiving or processing data or signals sBCH, eRS, PDCCH from system information); based on the failure to receive or process specific data or specific signals from the UE (e.g., based on the failure to receive or process data or signals sBCH, eRS, PDCCH from system information).

In an example, the radio access network of the wireless network may comprise at least one cell, optionally a small cell.

Example 30 may include the apparatus of example 29 or any other example herein, wherein the anchor eNB provides user-plane and control-plane communications between the at least one UE and the core network.

Example 31 may include the apparatus of example 29 or 30 or any other example herein, wherein the booster eNB provides user plane and control plane communications between the at least one UE and the anchor eNB.

Example 32 may include the apparatus of any one of examples 29 to 31 or any other example herein, wherein the booster eNB is in communication with the anchor eNB over an eNB-to-eNB communication link interface, optionally an X2 interface.

Example 33 may include the apparatus of any one of examples 29 to 32 or any other example herein, wherein the eNB provides at least two primary communication links with at least one UE, and wherein the one or more processors are further to divide traffic to be transmitted between the at least two primary communication links.

Example 34 may include the apparatus of example 33 or any other example herein, wherein dividing traffic to be transmitted between at least two primary communication links comprises providing at least two bearer links, wherein a bearer link is assigned to each primary communication link.

Example 35 may include the apparatus of any one of examples 29 to 34 or any other example herein, wherein the one or more processors are further to: a multi-connectivity convergence protocol (MCCP) stack entity is provided, wherein the MCCP stack entity operates above respective radio access network protocol sub-stacks, and wherein the MCCP stack entity manages how data traffic for at least one UE is routed over a primary communication link and a secondary communication link.

Example 36 may include the apparatus of any one of examples 29 to 35 or any other example herein, wherein operating above the respective radio access network protocol sub-stacks comprises operating above a Packet Data Convergence Protocol (PDCP) stack entity of each wireless communication link operating in the eNB.

Example 37 may include the apparatus of any one of examples 29 to 36 or any other example herein, wherein each wireless communication link operating in the eNB includes separate user plane and control plane stacks to provide operation independent of each other wireless communication link operating in the eNB.

Example 38 may include the apparatus of any one of examples 29 to 37 or any other example herein, wherein the one or more processors are further to provide PDCP bearer splitting by the MCCP stack entity.

Example 39 may include the apparatus of any one of examples 29 to 38 or any other example herein, wherein the MCCP stack entity comprises a user plane part MCCP-u and a control plane part MCCP-c.

Example 40 may include an eNB apparatus comprising the application processor, the memory, the one or more antenna ports, and an interface to allow the application processor to communicate with another apparatus, the eNB apparatus comprising the apparatus of any of examples 29 to 39.

Example 41 may include a machine-readable storage medium having machine-executable instructions that, when executed, cause one or more processors to perform operations in an evolved node b (enb) operable to communicate with a User Equipment (UE) over a wireless network, the operations comprising: selectively operating the eNB in a first operational state to act as an anchor eNB for the at least one UE, wherein operating as the anchor eNB includes providing communication between the at least one UE and a core network of a serving wireless network; and selectively operating the eNB to act as a booster eNB for the at least one UE in the second operational state, wherein operating as the booster eNB includes providing communication between the at least one UE and a radio access network of the wireless network; selecting between the first and second operating states based on information from the at least one UE.

Example 42 may include the machine-readable storage medium of example 41 or any other example herein, further comprising: user plane and control plane communications between at least one UE and a core network are provided.

Example 43 may include the machine-readable storage medium of example 41 or 42 or any other example herein, further comprising: user plane and control plane communications between at least one UE and an anchor eNB are provided by a booster eNB.

Example 44 may include the machine-readable storage medium of any one of examples 41 to 43 or any other example herein, further comprising: the anchor eNB communicates with the booster eNB over an eNB-to-eNB communication link interface, optionally over an X2 interface.

Example 45 may include the machine-readable storage medium of any one of examples 41 to 44 or any other example herein, further comprising: providing at least two primary communication links with at least one UE; and dividing traffic to be transmitted between the at least two primary communication links.

Example 46 may include the machine-readable storage medium of example 45 or any other example herein, wherein dividing traffic to be transmitted between at least two primary communication links comprises providing at least two bearer links, wherein a bearer link is assigned to each primary communication link.

Example 47 may include the machine-readable storage medium of any one of examples 41 to 46 or any other example herein, further comprising: a multi-connectivity convergence protocol (MCCP) stack entity is provided, wherein the MCCP stack entity operates above respective radio access network protocol sub-stacks, and wherein the MCCP stack entity manages how data traffic for at least one UE is routed over a primary communication link and a secondary communication link.

Example 48 may include the machine-readable storage medium of any one of examples 41 to 47 or any other example herein, wherein operating above the respective radio access network protocol sub-stacks comprises operating above a Packet Data Convergence Protocol (PDCP) stack entity of each wireless communication link operating in the eNB.

Example 49 may include the machine-readable storage medium of any one of examples 41 to 48, or any other example herein, further comprising: a separate user plane and control plane stack is provided for each other wireless communication link operating in the eNB.

Example 50 may include the machine-readable storage medium of any one of examples 41 to 49 or any other example herein, further comprising: PDCP bearer partitioning is provided by an MCCP stack entity.

Example 51 may include the machine-readable storage medium of any one of examples 41 to 50 or any other example herein, further comprising: a user plane part MCCP-u and a control plane part MCCP-c of the MCCP stack entity are provided.

Example 52 may include a method in an evolved node b (enb) operable to communicate with a User Equipment (UE) on a wireless network, comprising: selectively operating the eNB in a first operational state to act as an anchor eNB for the at least one UE, wherein operating as the anchor eNB includes providing communication between the at least one UE and a core network of a serving wireless network; and selectively operating the eNB to act as a booster eNB for the at least one UE in the second operational state, wherein operating as a booster eNB includes providing communication between the at least one UE and a radio access network of the wireless network; selecting between the first and second operating states based on information from the at least one UE.

Example 53 may include the method of example 52 or any other example herein, further comprising: user plane and control plane communications between at least one UE and a core network are provided.

Example 54 may include the method of example 52 or 53, or any other example herein, further comprising: user plane and control plane communications between at least one UE and an anchor eNB are provided by a booster eNB.

Example 55 may include the method of any one of examples 51 to 54 or any other example herein, further comprising: the anchor eNB communicates with the booster eNB over an eNB-to-eNB communication link interface, optionally over an X2 interface.

Example 56 may include the method of any one of examples 52 to 55 or any other example herein, further comprising: providing at least two primary communication links with at least one UE; and dividing traffic to be transmitted between the at least two primary communication links.

Example 57 may include the method of example 56 or any other example herein, wherein dividing traffic to be transmitted between at least two primary communication links comprises providing at least two bearer links, wherein a bearer link is assigned to each primary communication link.

Example 58 may include the method of any one of examples 52 to 57 or any other example herein, further comprising: a multi-connectivity convergence protocol (MCCP) stack entity is provided, wherein the MCCP stack entity operates above respective radio access network protocol sub-stacks, and wherein the MCCP stack entity manages how data traffic for at least one UE is routed over a primary communication link and a secondary communication link.

Example 59 may include the method of any one of examples 52 to 58 or any other example herein, wherein operating above the respective radio access network protocol sub-stacks comprises operating above a Packet Data Convergence Protocol (PDCP) stack entity of each wireless communication link operating in the eNB.

Example 60 may include the method of any one of examples 52 to 59 or any other example herein, further comprising: a separate user plane and control plane stack is provided for each other wireless communication link operating in the eNB.

Example 61 may include the method of any one of examples 52 to 60 or any other example herein, further comprising: PDCP bearer partitioning is provided by an MCCP stack entity.

Example 62 may include the method of any one of examples 52 to 61 or any other example herein, further comprising: a user plane part MCCP-u and a control plane part MCCP-c of the MCCP stack entity are provided.

Example 63 may include a machine-readable storage medium having machine-executable instructions that, when executed, cause one or more processors to perform operations for synchronizing neighboring cells using directional transmissions, the operations comprising: coordinating neighboring cells to maintain a fixed offset between transmissions of evolved node B (eNB) control signals, wherein the control signals include: primary Synchronization Signal (PSS) transmissions corresponding to one or more first eNB transmit and receive sectors, Secondary Synchronization Signal (SSS) transmissions corresponding to one or more second eNB transmit and receive sectors, and Sector Level Sweep (SLS) signals received by one or more UE transmit and receive sectors; and wherein the causing neighboring cells to cooperate comprises: broadcasting offset information to the UE, wherein the offset information comprises a neighbour cell ID k, a maximum number N of neighbour cells involved, and a fixed time offset T for use by the neighbour cell identified by k_offset。

Example 64 may include the machine-readable storage medium of example 63 or any other example herein, wherein the fixed time offset T is fixed if neighboring cells are tightly synchronized_offsetIs set to zero, wherein close synchronization includes being synchronized to a symbol or shorter period of time.

Example 65 may include the machine-readable storage medium of example 63 or 64 or any other example herein, wherein if the neighboring cells are not tightly synchronized, the method further comprises: a separate timing mechanism is maintained for each neighboring cell that is not tightly synchronized, wherein tight synchronization includes being synchronized to a symbol or shorter period of time.

Example 66 may include the machine-readable storage medium of example 65 or any other example herein, wherein maintaining a separate timing mechanism for each neighboring cell comprises maintaining a separate timer clock for each neighboring cell.

Example 67 may include the machine-readable storage medium of any one of examples 63 to 66 or any other example herein, further comprising: transmitting a Primary Synchronization Signal (PSS) transmission and a Secondary Synchronization Signal (SSS) transmission in succession in a first subframe transmission of each neighboring cell, and using a fixed time offset To_ffsetDelaying subsequent transmissions of Sector Level Sweep (SLS) signals for each neighboring cell, wherein the total delay for a given cell N is a fixed time offset T_offsetK times of; wherein a first subframe transmission of each neighboring cell containing a Primary Synchronization Signal (PSS) transmission and a Secondary Synchronization Signal (SSS) transmission is transmitted simultaneously across all neighboring cells.

Example 68 may include the machine-readable storage medium of any one of examples 63 to 67 or any other example herein, further comprising: transmitting a Primary Synchronization Signal (PSS) transmission, a Secondary Synchronization Signal (SSS) transmission, and a Sector Level Sweep (SLS) signal in succession in a first subframe transmission of each neighboring cell, wherein a fixed time offset T_offsetDelaying the transmission of the first subframe of each neighboring cell with respect to each other, wherein neighboring cell k delays the transmission of its first subframe by k fixed time offsets T_offset。

Example 69 may include the machine-readable storage medium of any one of examples 63 to 68 or any other example herein, wherein the Sector Level Scanning (SLS) comprises an exhaustive search to select a best transmitting sector on the eNB for the UE, wherein the SLS is performed by both the transmitter and the receiver.

Example 70 may include a method of synchronizing neighboring cells using directional transmissions, comprising: coordinating neighboring cells to maintain a fixed offset between transmissions of evolved node B (eNB) control signals, wherein the control signals include: primary Synchronization Signal (PSS) transmissions corresponding to one or more first eNB transmit and receive sectors and Secondary Synchronization Signal (SSS) transmissions corresponding to one or more second eNB transmit and receive sectors, and Sector Level Sweep (SLS) signals received by one or more UE transmit and receive sectors; and it isThe causing neighboring cells to cooperate comprises: broadcasting offset information to the UE, wherein the offset information comprises a neighbour cell ID k, a maximum number N of neighbour cells involved, and a fixed time offset T for use by the neighbour cell identified by k_offset。

Example 71 may include the method of example 70 or any other example herein, further comprising: if the neighboring cells are closely synchronized, the time offset T will be fixed_offsetSet to zero, wherein close synchronization includes synchronization to a symbol or shorter period of time.

Example 72 may include the method of example 70 or 71 or any other example herein, wherein if the neighboring cells are not tightly synchronized, the method further comprises: a separate timing mechanism is maintained for each cell that is not tightly synchronized, wherein tight synchronization includes synchronization to a symbol or shorter period of time.

Example 73 may include the method of example 72 or any other example herein, wherein maintaining a separate timing mechanism for each neighboring cell comprises maintaining a separate timer clock for each neighboring cell.

Example 74 may include the method of any one of examples 70 to 73 or any other example herein, further comprising: successively transmitting a Primary Synchronization Signal (PSS) transmission and a Secondary Synchronization Signal (SSS) transmission in a first subframe transmission of each neighboring cell; using a fixed time offset T_offsetDelaying subsequent transmissions of Sector Level Sweep (SLS) signals for each neighboring cell, wherein the total delay for a given cell N is a fixed time offset T_offsetK times of; and transmitting a Primary Synchronization Signal (PSS) transmission and a Secondary Synchronization Signal (SSS) transmission simultaneously across all neighboring cells in a first subframe transmission of each neighboring cell.

Example 75 may include the method of any one of examples 70 to 73 or any other example herein, further comprising: sequentially transmitting a Primary Synchronization Signal (PSS) transmission, a Secondary Synchronization Signal (SSS) transmission, and a Sector Level Scanning (SLS) signal in a first subframe transmission of each neighboring cell; wherein the time offset T is fixed_offsetSuch that the transmission of the first subframe of each neighboring cell is relative to each otherThis delay, where the neighboring cell k delays its transmission of the first subframe by k fixed time offsets T_offset。

Example 76 may include the method of any one of examples 70 to 75 or any other example herein, wherein the Sector Level Scanning (SLS) comprises an exhaustive search to select a best transmitting sector on the eNB for the UE, wherein the SLS is performed by the transmitter and the receiver.

Example 77 may include a machine-readable storage medium having machine-executable instructions that, when executed, cause one or more processors to perform operations in a UE to detect a loss of a communication link, the operations comprising: receiving a communication over a communication link; and determining that the communication link is lost (or broken) by determining incorrect receipt of at least one of a plurality of predetermined communication types on the communication link; wherein the plurality of predetermined communication types includes: a Physical Downlink Control Channel (PDCCH), a dedicated link loss detection broadcast located in a portion of a subframe received after the PDCCH and having a set of link loss detection broadcast parameters, and an enhanced reference signal (eRS) persistently allocated for each of a fixed number of Transmission Time Intervals (TTIs) associated with the communication link; and wherein the incorrect reception of the PDCCH, dedicated link loss detection broadcast, or enhanced reference signal comprises a failure to receive the PDCCH, dedicated link loss detection broadcast, or enhanced reference signal for a predetermined period of time on a given sector of an evolved node b (enb).

Example 78 may include the machine-readable storage medium of example 77 or any other example herein, wherein eRS is mapped onto a predetermined sector of the eNB.

Example 79 may include the machine-readable storage medium of example 77 or 78, or any other example herein, wherein eRS includes the cell ID information.

Example 80 may include the machine-readable storage medium of any one of examples 77 to 79 or any other example herein, wherein the time and frequency allocation of radio resources of eRS is mapped to an eNB sector index.

Example 81 may include a method of detecting a loss of a communication link in a UE, comprising: receiving a communication over a communication link; and determining that the communication link is lost (broken) by determining incorrect receipt of at least one of a plurality of predetermined communication types over the communication link; wherein the plurality of predetermined communication types includes: a Physical Downlink Control Channel (PDCCH), a dedicated link loss detection broadcast located in a portion of a subframe received after the PDCCH and having a set of link loss detection broadcast parameters, and an enhanced reference signal (eRS) allocated for each of a fixed number of Transmission Time Intervals (TTIs) associated with the communication link; and wherein the incorrect reception of the PDCCH, dedicated link loss detection broadcast, or enhanced reference signal comprises a failure to receive the PDCCH, dedicated link loss detection broadcast, or enhanced reference signal for a predetermined period of time on a given sector of an evolved node b (enb).

Example 82 may include the method of example 81 or any other example herein, wherein eRS is mapped onto a predetermined sector of the eNB.

Example 83 may include the method of example 81 or 82 or any other example herein, wherein eRS includes the cell ID information.

Example 84 may include the method of any one of examples 82 to 83 or any other example herein, wherein the time and frequency allocation of radio resources of eRS is mapped to an eNB sector index.

Example 85 may include an apparatus of a User Equipment (UE) operable to communicate with an evolved node b (enb) on a wireless network, comprising: one or more processors configured to: processing a communication signal received over a communication link; and determining that the communication link is lost (or broken) by determining incorrect receipt of at least one of a plurality of predetermined communication types over the communication link; wherein the plurality of predetermined communication types includes: a dedicated downlink control channel (PDCCH), a dedicated link loss detection broadcast located in a portion of a subframe received after the PDCCH and having a set of link loss detection broadcast parameters, and an enhanced reference signal (eRS) persistently allocated for each of a fixed number of Transmission Time Intervals (TTIs) associated with the communication link; and wherein the incorrect reception of the PDCCH, dedicated link loss detection broadcast, or enhanced reference signal comprises a failure to receive the PDCCH, dedicated link loss detection broadcast, or enhanced reference signal for a predetermined period of time on a given sector of an evolved node b (enb).

Example 86 may include the apparatus of example 85 or any other example herein, wherein eRS is mapped onto a predetermined sector of an eNB.

Example 87 may include the apparatus of example 85 or 86 or any other example herein, wherein eRS includes the cell ID information.

Example 88 includes the apparatus of any one of examples 85 to 87, wherein the time and frequency allocation of radio resources of eRS is mapped to an eNB sector index.

Example 89 may include a machine-readable storage medium having machine-executable instructions that, when executed, cause one or more processors to perform operations for detecting a loss of a communication link in a User Equipment (UE), the operations comprising: receiving a set of link loss detection broadcast parameters; and detecting reception of a link loss detection broadcast using the set of link loss detection broadcast parameters; wherein the operations further comprise: determining a lost communication link associated with the link loss detection broadcast when the link loss detection broadcast is not properly received; or when the link loss detection broadcast is correctly received, determining that the communication link associated with the link loss detection broadcast is available; wherein the link loss detection broadcast parameters include: t is_sBCHA link loss detection broadcast interval; k is the number of symbols in the Physical Downlink Control Channel (PDCCH); n is the maximum number of symbols broadcast by link loss detection; and M is the link loss detection threshold.

Example 90 may include the machine-readable storage medium of example 89 or any other example herein, wherein the link loss detection broadcasts a radio resource after being allocated to the PDCCH.

Example 91 may include the machine-readable storage medium of example 89 or 90 or any other example herein, wherein the radio resources allocated to the link loss detection broadcast are configured by system information.

Example 92 may include the machine-readable storage medium of any one of examples 89 to 91 or any other example herein, wherein the link loss detection broadcast has a variable length up to a maximum length provided to the UE prior to reception.

Example 93 may include the machine-readable storage medium of any one of examples 89 to 92 or any other example herein, wherein the link loss detection broadcast comprises a cell identification (cell ID) and a sector index.

Example 94 may include a method in a User Equipment (UE) of detecting a loss of a communication link, comprising: receiving a set of link loss detection broadcast parameters; and detecting reception of a link loss detection broadcast using the set of link loss detection broadcast parameters; wherein the operations further comprise: determining a lost communication link associated with the link loss detection broadcast when the link loss detection broadcast is not properly received; or when the link loss detection broadcast is correctly received, determining that the communication link associated with the link loss detection broadcast is available; wherein the link loss detection broadcast parameters include: t is_sBCHA link loss detection broadcast interval; k is the number of symbols in the Physical Downlink Control Channel (PDCCH); n is the maximum number of symbols broadcast by link loss detection; and M is the link loss detection threshold.

Example 95 may include the method of example 94 or any other example herein, wherein the link loss detection broadcasts a radio resource after being allocated to the PDCCH.

Example 96 may include the method of example 94 or 95 or any other example herein, wherein the radio resources allocated to the link loss detection broadcast are configured by system information.

Example 97 may include the method of any one of examples 94 to 96 or any other example herein, wherein the link loss detection broadcast has a variable length up to a maximum length provided to the UE prior to reception.

Example 98 may include the method of any one of examples 94 to 97 or any other example herein, wherein the link loss detection broadcast includes a cell identification (cell ID) and a sector index.

Example 99 may include an apparatus of a User Equipment (UE) operable to communicate with an evolved node b (enb) on a wireless network, comprising: one or more processors configured to: receiving a set of link loss detection broadcast parameters; and detecting reception of a link loss detection broadcast using the set of link loss detection broadcast parameters; determining a lost communication link associated with the link loss detection broadcast when the link loss detection broadcast is not properly received; or when the link loss detection broadcast is correctly received, determining that the communication link associated with the link loss detection broadcast is available; wherein the link loss detection broadcast parameters include: t is_sBCHA link loss detection broadcast interval; k is the number of symbols in the Physical Downlink Control Channel (PDCCH); n is the maximum number of symbols broadcast by link loss detection; and M is the link loss detection threshold.

Example 100 may include the apparatus of example 99 or any other example herein, wherein the link loss detection broadcasts a radio resource after being allocated to the PDCCH.

In an example, the radio resources may comprise a portion of a subframe transmission, i.e., one or more physical resource blocks.

Example 101 may include the apparatus of example 99 or 100 or any other example herein, wherein the wireless link allocated to the link loss detection broadcast is configured by system information.

Example 102 may include the apparatus of any one of examples 99 to 101 or any other example herein, wherein the link loss detection broadcast has a variable length up to a maximum length provided to the UE prior to reception.

Example 103 may include the apparatus of any one of examples 99 to 102 or any other example herein, wherein the link loss detection broadcast comprises a cell identification (cell ID) and a sector index.

Example 104 may include a machine-readable storage medium having machine-executable instructions that, when executed, causeOne or more processors are configured to perform a method of detecting a loss of a communication link in an evolved node b (enb), the method comprising: transmitting a set of link loss detection broadcast parameters; and transmitting a link loss detection broadcast according to the set of link loss detection broadcast parameters; wherein the link loss detection broadcast parameters include: t is_sBCHA link loss detection broadcast interval; k is the number of symbols in the Physical Downlink Control Channel (PDCCH); n is the maximum number of symbols broadcast by link loss detection; and M is the link loss detection threshold.

Example 105 may include the machine-readable storage medium of example 104 or any other example herein, wherein the link loss detection broadcast is allocated to a radio resource before or after the PDCCH.

Example 106 may include the machine-readable storage medium of example 104 or 105 or any other example herein, wherein the radio resources allocated to the link loss detection broadcast are configured by system information.

Example 107 may include the machine-readable storage medium of any one of examples 104 to 106 or any other example herein, wherein the link loss detection broadcast has a variable length up to a maximum length provided to a User Equipment (UE) prior to reception.

Example 108 may include the machine-readable storage medium of any one of examples 104 to 107 or any other example herein, wherein the link loss detection broadcast comprises a cell identification (cell ID) and a sector index.

Example 109 may include the machine-readable storage medium of any one of examples 104 to 108 or any other example herein, wherein the directional transmission comprises a millimeter wave transmission.

Example 110 may include the machine-readable storage medium of any one of examples 104 to 109 or any other example herein, wherein the link loss detection broadcast parameters are transmitted via system information.

Example 111 may include the machine-readable storage medium of any one of examples 104 to 110 or any other example herein, wherein the link loss detection broadcast comprises an enhanced reference signal (eRS) or a shortened broadcast channel (sBCH) that is persistently allocated for each Transmission Time Interval (TTI) associated with the communication link.

Example 112 may include the machine-readable storage medium of any one of examples 104 to 111 or any other example herein, wherein the persistent allocation comprises allocation of time and frequency radio resources to a duration.

Example 113 may include a method in an evolved node b (enb) of detecting a loss of a communication link, the method comprising: transmitting a set of link loss detection broadcast parameters; and transmitting a link loss detection broadcast according to the set of link loss detection broadcast parameters; wherein the link loss detection broadcast parameters include: t is_sBCHA link loss detection broadcast interval; k is the number of symbols in the Physical Downlink Control Channel (PDCCH); n is the maximum number of symbols broadcast by link loss detection; and M is the link loss detection threshold.

Example 114 may include the method of example 113 or any other example herein, further comprising: a link loss detection broadcast is allocated to a radio resource before or after the PDCCH.

Example 115 may include the method of example 113 or 114, or any other example herein, to configure the radio resources allocated to the link loss detection broadcast by the system information.

Example 116 may include the method of any one of examples 113 to 115 or any other example herein, wherein the link loss detection broadcast has a variable length up to a maximum length provided to the UE prior to reception.

Example 117 may include the method of any one of examples 113 to 116 or any other example herein, wherein the link loss detection broadcast comprises a cell identification (cell ID) and a sector index.

Example 118 may include the method of any one of examples 113 to 117 or any other example, wherein the directional transmission comprises a millimeter wave transmission.

Example 119 may include the method of any one of examples 113 to 118 or any other example herein, further comprising: the link loss detection broadcast parameters are transmitted via system information.

Example 120 may include the method of any one of examples 113 to 119 or any other example herein, wherein the link loss detection broadcast comprises an enhanced reference signal (eRS) or a shortened broadcast channel (sBCH) that is persistently allocated for each Transmission Time Interval (TTI) associated with the communication link.

Example 121 may include the method of any one of examples 113 to 120 or any other example herein, wherein the persistent allocation comprises allocation to persistent time and frequency radio resources.

Example 122 may include an apparatus of an evolved node b (enb) operable to communicate with a User Equipment (UE) in a wireless network, comprising: one or more processors configured to: transmitting a set of link loss detection broadcast parameters; and transmitting a link loss detection broadcast according to the set of link loss detection broadcast parameters; wherein the link loss detection broadcast parameters include: t is_sBCHA link loss detection broadcast interval; k is the number of symbols in the Physical Downlink Control Channel (PDCCH); n is the maximum number of symbols broadcast by link loss detection; and M is the link loss detection threshold.

Example 123 may include the apparatus of example 122 or any other example herein, wherein the link loss detection broadcast is allocated to radio resources before or after the PDCCH.

Example 124 may include the apparatus of example 122 or 123, or any other example herein, wherein the radio resources allocated to the link loss detection broadcast are configured by system information.

Example 125 may include the apparatus of any one of examples 122 to 124 or any other example herein, wherein the link loss detection broadcast has a variable length up to a maximum length provided to the UE prior to reception.

Example 126 may include the apparatus of any one of examples 122 to 125 or any other example herein, wherein the link loss detection broadcast comprises a cell identification (cell ID) and a sector index.

Example 127 may include the apparatus of any one of examples 122 to 126 or any other example herein, wherein the directional transmission comprises a millimeter wave transmission.

Example 128 may include the apparatus of any one of examples 122 to 127 or any other example herein, wherein the link loss detection broadcast parameters are transmitted via system information.

Example 129 may include the apparatus of any one of examples 104 to 128 or any other example herein, wherein the link loss detection broadcast comprises an enhanced reference signal (eRS) or a shortened broadcast channel (sBCH) allocated for each Transmission Time Interval (TTI) associated with the communication link.

Example 130 may include the apparatus of any one of examples 104 to 111 or any other example herein, wherein the persistent allocation comprises allocation to persistent time and frequency radio resources.

Example 131 may include a machine-readable storage medium having machine-executable instructions that, when executed, cause one or more processors to perform operations between a User Equipment (UE) and at least two wireless network cells, the operations comprising: maintaining a primary communication link with a first network cell; maintaining a secondary communication link with a second network cell; and forming a persistent Uplink (UL) scheduling request message (pSR REQ message (UL)) for transmission on the secondary communication link; wherein forming the persistent UL scheduling request message comprises: receiving a first offset value d_pSR-REQA first offset value indicating a symbol offset between a first symbol of a persistent UL scheduling request message transmitted on an uplink and a last symbol that can be used for Downlink (DL)/Uplink (UL) allocation in a corresponding subframe; receiving a second offset value d_pSR-RSPA second offset value indicating a symbol offset between the first symbol of the persistent UL scheduling request message and the first symbol of the persistent UL scheduling response message; receiving a cycle time T of a persistent UL scheduling request message in units of time slots or subframes_pSR(ii) a And forming a persistent UL scheduling request message according to the received first offset value, second offset value, and cycle time.

Example 132 may include the machine-readable storage medium of example 131 or any other example herein, further comprising: a persistent UL scheduling response message (pSR Resp message (UL)) is received on the secondary communication link based on the received first offset value, second offset value, and cycle time.

Example 133 may include the machine-readable storage medium of example 131 or 132 or any other example herein, wherein forming the persistent UL scheduling request message from the received first offset value, second offset value, and cycle time comprises: a location in the subframe to transmit the persistent UL scheduling request message is determined using the first offset, the location being associated with an end of the subframe at which the persistent UL scheduling request message is transmitted.

Example 134 may include the machine-readable storage medium of any one of examples 131 to 133 or any other example herein, wherein forming the persistent UL scheduling response message from the received first offset value, second offset value, and cycle time comprises: the method further includes determining a location in the subframe to transmit the persistent UL scheduling request message using the first offset, the location being related to an end of the subframe at which the persistent UL scheduling request message is transmitted, and determining a second location in the subframe to transmit the persistent UL scheduling response message using the second offset value, the second location being related to the first location.

Example 135 may include the machine-readable storage medium of any one of examples 131 to 134 or any other example herein, wherein the location in the subframe at which the persistent UL scheduling request message is transmitted is at a symbol distance d from an end of the subframe or a first symbol of a common control and reference signal (primary synchronization signal (PSS) or Secondary Synchronization Signal (SSS)/broadcast signal (BCH)/sector-level sweep (SLS))_pSR-REQAt the location of (a).

Example 136 may include the machine-readable storage medium of any one of examples 131 to 135 or any other example herein, wherein the second location in the subframe at which the persistent UL scheduling response message is transmitted is at a symbol distance d from a beginning of the UL scheduling request message_pSR-RSPAt the location of (a).

Example 137 may include the machine-readable storage medium of any one of examples 131 to 136, or any other example herein, further comprising: a persistent UL scheduling request (pSR) message is transmitted on the secondary communication link.

Example 138 may include the machine-readable storage medium of any one of examples 131 to 137 or any other example herein, further comprising: a persistent UL scheduling response message is transmitted on the secondary communication link.

Example 139 may include a method in a UE, comprising: maintaining a primary communication link with a first network cell; maintaining a secondary communication link with a second network cell; and forming a persistent Uplink (UL) scheduling request message (pSR REQ message (UL)) for transmission on the secondary communication link; wherein forming the persistent UL scheduling request message comprises: receiving a first offset value d_pSR-REQA first offset value indicating a symbol offset between a first symbol of a persistent UL scheduling request message transmitted on an uplink and a last symbol that can be used for Downlink (DL)/Uplink (UL) allocation in a corresponding subframe; receiving a second offset value d_pSR-RSPA second offset value indicating a symbol offset between the first symbol of the persistent UL scheduling request message and the first symbol of the persistent UL scheduling response message; receiving a cycle time T in units of slots or subframes for a persistent UL scheduling request message_pSR(ii) a And forming a persistent UL scheduling request message according to the received first offset value, second offset value, and cycle time.

Example 140 may include the method of example 139 or any other example herein, further comprising: a persistent UL scheduling response message (pSR Resp message (UL)) is received on the secondary communication link based on the received first offset value, second offset value, and cycle time.

Example 141 may include the method of example 139 or 140 or any other example herein, wherein forming the persistent UL scheduling request message from the received first offset value, second offset value, and cycle time comprises: a location in the subframe to transmit the persistent UL scheduling request message is determined using the first offset, the location being associated with an end of the subframe at which the persistent UL scheduling request message is transmitted.

Example 142 may include the method of any one of examples 139 to 141 or any other example herein, wherein forming the persistent UL scheduling response message from the received first offset value, second offset value, and cycle time comprises: the method further includes determining a location in the subframe to transmit the persistent UL scheduling request message using the first offset, the location being related to an end of the subframe at which the persistent UL scheduling request message is transmitted, and determining a second location in the subframe to transmit the persistent UL scheduling response message using the second offset value, the second location being related to the first location.

Example 143 may include the method of any one of examples 139 to 142 or any other example herein, wherein a location in a subframe at which a persistent UL scheduling request message is transmitted is at a symbol distance d from an end of the subframe or a first symbol of a common control and reference signal (primary synchronization signal (PSS)/Secondary Synchronization Signal (SSS)/Broadcast Channel (BCH)/sector-level sweep (SLS))_pSR-REQThe position of (a).

Example 144 may include the method of any one of examples 139 to 144 or any other example herein, wherein the second position in the subframe at which the persistent UL scheduling response message is transmitted is at a symbol distance d from a beginning of the UL scheduling request message_pSR-RSPThe position of (a).

Example 145 may include the method of any one of examples 139 to 144 or any other example herein, further comprising: a persistent UL scheduling request (pSR) message is transmitted on the secondary communication link.

Example 146 may include the method of any one of examples 139 to 145 or any other example herein, further comprising: a persistent UL scheduling response message is transmitted on the secondary communication link.

Example 147 may include an apparatus of a User Equipment (UE) operable to communicate with an evolved node b (enb) in a wireless network, comprising: one or more processors configured to: maintaining a primary communication link with a first network cell; maintaining a secondary communication link with a second network cell; and forming a persistent Uplink (UL) scheduling request message (pSR REQ message (UL)) for transmission on the secondary communication link; wherein to form a persistent UL scheduling request message, the one or more processors are to: receiving a first offset value d_pSR-REQThe first offset value indicates that a first symbol of a persistent UL scheduling request message transmitted on an uplink and a corresponding subframe can be used for Downlink (DL)/uplinkSymbol offset between last cells of a Uplink (UL) allocation; receiving a second offset value d_pSR-RSPA second offset value indicating a symbol offset between the first symbol of the persistent UL scheduling request message and the first symbol of the persistent UL scheduling response message; receiving a cycle time T in units of slots or subframes for a persistent UL scheduling request message_pSR(ii) a And forming a persistent UL scheduling request message according to the received first offset value, second offset value, and cycle time.

Example 148 may include the apparatus of example 147 or any other example herein, wherein the one or more processors are further to receive a persistent UL scheduling response message (pSR Resp message (UL)) on the secondary communication link according to the received first offset value, second offset value, and cycle time.

Example 149 may include the apparatus of example 147 or 148 or any other example herein, wherein the one or more processors being further to form the persistent UL scheduling request message according to the received first offset value, second offset value, and cycle time comprises: a location in the subframe to transmit the persistent UL scheduling request message is determined using the first offset, the location being associated with an end of the subframe at which the persistent UL scheduling request message is transmitted.

Example 150 may include the apparatus of any one of examples 147 to 149 or any other example herein, wherein the one or more processors being further configured to form the persistent UL scheduling response message from the received first offset value, second offset value, and cycle time comprises: the method further includes determining a location in the subframe to transmit the persistent UL scheduling request message using the first offset, the location being related to an end of the subframe at which the persistent UL scheduling request message is transmitted, and determining a second location in the subframe to transmit the persistent UL scheduling response message using the second offset value, the second location being related to the first location.

Example 151 may include the apparatus of any one of examples 147 to 150 or any other example herein, wherein a location in a subframe at which the persistent UL scheduling request message is transmitted is at the end of the subframe or at a common control and reference signal (primary synchronization signal (PSS)/Secondary Synchronization Signal (SSS)/broadcast signal (BCH)/sector level sweep(SLS)) the first symbol of the first symbol is a symbol distance d_pSR-REQAt the location of (a).

Example 152 may include the apparatus of any one of examples 147 to 151 or any other example herein, wherein the second position in the subframe at which the persistent UL scheduling response message is transmitted is at a symbol distance d from a beginning of the UL scheduling request message_pSR-RSPAt the location of (a).

Example 153 may include the apparatus of any one of examples 147 to 152 or any other example herein, wherein the one or more processors are further to transmit a persistent UL scheduling request (pSR) message on the secondary communication link.

Example 154 may include the apparatus of any one of examples 147 to 153 or any other example herein, wherein the one or more processors are further to transmit the persistent UL scheduling response message on the secondary communication link.

Example 155 may include a machine-readable storage medium having machine-executable instructions that, when executed, cause one or more processors to perform operations between a User Equipment (UE) and at least two wireless network cells, the operations comprising: maintaining at least one primary communication link between the UE and the first network cell and transmitting and receiving data between the UE and the wireless network using the at least one primary communication link; maintaining at least one secondary communication link between the UE and the second network cell, and transmitting and receiving control messages (e.g., scheduling requests) between the UE and the wireless network using the at least one secondary communication link; detecting a loss of the primary communication link; and performing a fast cell handover (FCS) procedure at the UE to switch communication from the lost at least one primary communication link to using one of the at least one secondary communication link.

Example 156 may include the machine-readable storage medium of example 155 or any other example herein, wherein the FCS process comprises: selecting an appropriate one of the at least one secondary communication link; transmitting an FCS handover request control message over the selected secondary communication link to an evolved node B (eNB) providing the secondary communication link; receiving an FCS handover response control message from an eNB providing the secondary communication link.

Example 157 may include the machine-readable storage medium of example 155 or 156 or any other example herein, wherein the FCS process further includes: setting the eNB providing the secondary communication link as a new primary eNB providing a new primary communication link; and transmitting and receiving all data between the UE and the wireless network on the new primary communication link.

Example 158 may include the machine-readable storage medium of any one of examples 155 to 157 or any other example herein, wherein transmitting the FCS handover request message on the selected secondary communication link to the eNB providing the secondary communication link comprises transmitting the FCS handover request in a persistent scheduling request message (pSR-REQ).

Example 159 may include the machine-readable storage medium of any one of examples 155 to 158 or any other example herein, wherein receiving the FCS handover response message from the eNB providing the secondary communication link comprises receiving the FCS handover response in a persistent scheduling response message (pSR-RSP).

Example 160 may include the machine-readable storage medium of any one of examples 155 to 159, or any other example herein, wherein the operations of examples 155 to 159 are performed in a UE.

Example 161 may include a method in a User Equipment (UE), comprising: maintaining at least one primary communication link between the UE and the first network cell, and transmitting and receiving data between the UE and the wireless network using the at least one primary communication link; maintaining at least one secondary communication link between the UE and the second network cell, and transmitting and receiving control messages (e.g., scheduling requests) between the UE and the wireless network using the at least one secondary communication link; detecting a loss of the primary communication link; and performing a fast cell handover (FCS) procedure at the UE to switch communications from the lost at least one primary communication link to using one of the at least one secondary communication link.

Example 162 may include the method of example 161 or any other example herein, wherein the FCS procedure comprises: selecting an appropriate one of the at least one secondary communication link; transmitting an FCS handover request control message over the selected secondary communication link to an evolved node B (eNB) providing the secondary communication link; receiving an FCS handover response control message from an eNB providing the secondary communication link.

Example 163 may include the method of example 161 or 162 or any other example herein, wherein the FCS procedure further includes: setting the eNB providing the secondary communication link as a new primary eNB providing a new primary communication link; and transmitting and receiving all data between the UE and the wireless network on the new primary communication link.

Example 164 may include the method of any one of examples 161 to 163 or any other example herein, wherein transmitting the FCS handover request message on the selected secondary communication link to the eNB providing the secondary communication link comprises transmitting the FCS handover request in a persistent scheduling request message (pSR-REQ).

Example 165 may include the method of any one of examples 161 to 164 or any other example herein, wherein receiving the FCS handover response message from the eNB providing the secondary communication link comprises receiving the FCS handover response in a persistent scheduling response message (pSR-RSP).

Example 166 may include an apparatus for a User Equipment (UE), comprising: one or more processors configured to: maintaining at least one primary communication link between the UE and the first network cell, and transmitting and receiving data between the UE and the wireless network using the at least one primary communication link; maintaining at least one secondary communication link between the UE and the second network cell, and transmitting and receiving control messages (e.g., scheduling requests) between the UE and the wireless network using the at least one secondary communication link; detecting a loss of the primary communication link; and performing a fast cell handover (FCS) procedure at the UE to switch communication from the lost at least one primary communication link to using one of the at least one secondary communication link.

Example 167 may include the apparatus of example 166, wherein the one or more processors are further to: selecting an appropriate one of the at least one secondary communication link; transmitting an FCS handover request control message over the selected secondary communication link to an evolved node B (eNB) providing the secondary communication link; receiving an FCS handover response control message from an eNB providing the secondary communication link.

Example 168 may include the apparatus of examples 166 or 167 or any other example herein, wherein the one or more processors are further to: setting the eNB providing the secondary communication link as a new primary eNB providing a new primary communication link; and transmitting and receiving all data between the UE and the wireless network on the new primary communication link.

Example 169 may include the apparatus of any one of examples 166 to 168 or any other example herein, wherein the one or more processors are further to transmit the FCS handover request to the eNB in a persistent scheduling request message (pSR-REQ).

Example 170 may include the apparatus of any one of examples 166 to 169 or any other example herein, wherein the one or more processors are further to receive, from the eNB, the FCS handover response message in a persistent scheduling response message (pSR-RSP).

Example 171 may include a machine-readable storage medium having machine-executable instructions that, when executed, cause one or more processors to perform operations between a User Equipment (UE) and at least two wireless network cells, the operations comprising: maintaining at least one primary communication link between the UE and a first evolved node b (enb) of a first network cell, and transmitting and receiving data between the UE and the wireless network using the at least one primary communication link; maintaining at least one secondary communication link between the UE and a second eNB of a second network cell, and transmitting and receiving persistent scheduling messages between the UE and the wireless network using the at least one secondary communication link; receiving a fast cell handover request message from the UE at a second eNB providing a secondary network cell when one of the at least one primary communication link for the UE is lost; transmitting a fast cell handover response message from a second eNB providing a secondary network cell to the UE over a secondary communication link; sending a fast cell handover notification message from the second eNB to an anchor eNB providing communication between the UE and a core network of the serving wireless network to control the first eNB to forward all communications of the UE to the second eNB for onward transmission by the second eNB to the UE.

Example 172 may include the machine-readable storage medium of example 171 or any other example herein, further comprising: a sector scanning procedure is initiated at the second eNB to select the most appropriate sector of the second eNB for communication with the UE.

Example 173 may include the machine-readable storage medium of example 171 or 172 or any other example herein, wherein selecting a most appropriate sector of the second eNB for communicating with the UE comprises selecting a sector having selection parameters that exceed a predetermined threshold.

Example 174 may include the machine-readable storage medium of any one of examples 171 to 173 or any other example herein, wherein receiving the fast cell handover request message from the UE at the second eNB comprises receiving the FCS handover request in a persistent scheduling request message (pSR-REQ).

Example 175 may include the machine-readable storage medium of any one of examples 171 to 174 or any other example herein, wherein transmitting the FCS handover response message from the second eNB includes transmitting the FCS handover response in a persistent scheduling response message (pSR-RSP).

Example 176 may include the machine-readable storage medium of any one of examples 171 to 175 or any other example herein, further comprising: detecting a loss of the primary communication link according to any one of examples 81 to 84 or 94 to 98.

Example 177 may include the machine-readable storage medium of any one of examples 171 to 176 or any other example herein, wherein the operations are performed in an eNB.

Example 178 may include a method in an evolved node b (enb), comprising: maintaining at least one primary communication link between a User Equipment (UE) and a first eNB of a first network cell, and transmitting and receiving data between the UE and a wireless network using the at least one primary communication link; maintaining at least one secondary communication link between the UE and a second eNB of a second network cell, and transmitting and receiving persistent scheduling messages between the UE and the wireless network using the at least one secondary communication link; receiving a fast cell handover request message from the UE at a second eNB providing a secondary network cell when one of the at least one primary communication link to the UE is lost; transmitting a fast cell handover response message from a second eNB providing a secondary network cell to the UE over a secondary communication link; sending a fast cell handover notification message from the second eNB to the anchor eNB to control the first eNB to forward all communications of the UE to the second eNB for onward transmission by the second eNB to the UE, wherein the anchor eNB provides communications between the UE and a core network of the serving wireless network.

Example 179 may include the method of example 178 or any other example herein, further comprising: a sector scanning procedure is initiated at the second eNB to select the most appropriate sector of the second eNB for communication with the UE.

Example 180 may include the method of example 178 or 179, or any other example herein, wherein selecting a most appropriate sector of the second eNB for communicating with the UE comprises: a sector is selected having a selection parameter exceeding a predetermined threshold.

Example 181 may include the method of any one of examples 178 to 180 or any other example herein, wherein receiving the fast cell handover request message from the UE at the second eNB comprises receiving the FCS handover request in a persistent scheduling request message (pSR-REQ).

Example 182 may include the method of any one of examples 178 to 181 or any other example herein, wherein transmitting the FCS handover response message from the second eNB includes transmitting the FCS handover response in a persistent scheduling response message (pSR-RSP).

Example 183 may include the method of any one of examples 178 to 182, or any other example herein, further comprising: detecting a loss of the primary communication link according to any one of examples 81 to 84 or 94 to 98.

Example 184 may include an apparatus for an evolved node b (enb), comprising: one or more processors configured to: maintaining at least one primary communication link between a User Equipment (UE) and a first eNB of a first network cell, and transmitting and receiving data between the UE and a wireless network using the at least one primary communication link; maintaining at least one secondary communication link between the UE and a second eNB of a second network cell, and transmitting and receiving persistent scheduling messages between the UE and the wireless network using the at least one secondary communication link; receiving a fast cell handover request message from the UE at a second eNB providing a secondary network cell when one of the at least one primary communication link to the UE is lost; transmitting a fast cell handover response message from a second eNB providing a secondary network cell to the UE over a secondary communication link; sending a fast cell handover notification message from the second eNB to the anchor eNB to control the first eNB to forward all communications of the UE to the second eNB for onward transmission by the second eNB, wherein the anchor eNB provides communications between the UE and a core network of the serving wireless network.

Example 185 may include the apparatus of example 184 or any other example herein, wherein the one or more processors are further to initiate a sector scanning procedure at the second eNB to select a most appropriate sector of the second eNB for communicating with the UE.

Example 186 may include the apparatus of any one of examples 184 or 185 or any other example herein, wherein the one or more processors are further to select a most appropriate sector of the second eNB for communicating with the UE according to a selection parameter exceeding a predetermined threshold.

Example 187 may include the apparatus of any one of examples 184 to 186 or any other example herein, wherein the one or more processors are further to receive, at the second eNB, the fast cell handover request message from the UE to be included in a persistent scheduling request message (pSR-REQ).

Example 188 may include the apparatus of any one of examples 184 to 187 or any other example herein, wherein the one or more processors are further to transmit the FCS handover response in a persistent scheduling response message (pSR-RSP).

Example 189 may include the apparatus of any one of examples 184-188 or any other example herein, wherein the one or more processors are further to detect a loss of the primary communication link according to any one of examples 81-84 or 94-98.

Example 190 may include an apparatus comprising means for performing any one of method examples 21-28, 52-62, 70-76, 81-84, 94-98, 113-121, 139-146, 161-165, and 178-183. Unless specifically indicated to be incompatible, or the physical structure of the embodiments or others, examples, or claims prohibit such combinations, the features of the foregoing embodiments and examples, and the appended claims may be integrated together in any suitable arrangement, particularly where it is advantageous to do so. This is not limited to any particular advantage, but may instead result in a post-hoc benefit. That is, the combination of features is not limited by the form described, and in particular, by the form (e.g., number) of the citation, example, or embodiment of the claims. Further, it is also intended that the phrases "in one embodiment," "according to an embodiment," and the like are merely grammatical forms of words and should not be construed as limiting features of different embodiments to all other instances of the same or similar words. That is, references to "an", "one", or "some" embodiment(s) may be a reference to any one or more and/or all embodiments, or combinations thereof, disclosed. In addition, similarly, reference to "this" embodiment is not limited to the immediately preceding embodiment. The abstract is provided to allow the reader to ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to limit the scope or meaning of the claims. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment.

Claims

1. An apparatus of a User Equipment (UE) operable to communicate with a base station on a wireless network, comprising:

one or more processors configured to:

maintaining a plurality of radio access network communication links between the UE and at least two base stations of a radio access network of the wireless network, wherein at least a first base station is an anchor base station, and wherein at least a second base station is a booster base station, the plurality of radio access network communication links between the UE and a radio access network of the wireless network including at least one primary communication link configured to transmit and receive data of the UE and at least one secondary communication link configured to maintain uplink synchronization and issue a request to switch the anchor base station and the booster base station; and

switching from actively using the at least one primary communication link to transmit and receive data for the UE to actively using the at least one secondary communication link when the at least one primary communication link is determined to be lost;

wherein the anchor base station is operable to provide communication between the UE and a core network serving the wireless network and communication between the UE and a radio access network providing the wireless network; and is

Wherein the booster base station is operable to provide communication between the UE and the radio access network providing the wireless network, and is operable to communicate with the core network only via the anchor base station.

2. The apparatus of claim 1, wherein the at least one secondary communication link is configured to transmit a persistent scheduling request (pSR) at each transmission time interval.

3. The apparatus of claim 1, wherein the at least one primary communication link is determined to be lost when a control signal is not received or incorrectly received.

4. The apparatus of claim 3, wherein the control signal comprises:

a physical downlink control channel PDCCH is used,

shortening the broadcast channel sBCH, or

The enhanced reference signal eRS is continuously allocated for each of a fixed number of transmission time intervals, TTIs.

5. The apparatus of claim 1, wherein the anchor base station provides user plane and control plane communications between the UE and the core network.

6. The apparatus of claim 1, wherein the booster base station provides user plane and control plane communications between the UE and the anchor base station.

7. The apparatus of claim 1, wherein the booster base station communicates with the anchor base station over a base station to base station communication link interface, optionally an X2 interface.

8. The apparatus of claim 1, wherein the UE maintains at least two primary communication links, and wherein the one or more processors are further configured to partition traffic to be transmitted between the at least two primary communication links.

9. The apparatus of claim 8, wherein dividing traffic to be transmitted between the at least two primary communication links comprises providing at least two bearer links, wherein a bearer link is assigned to each primary communication link.

10. The apparatus of claim 1, wherein the one or more processors are further to:

providing a multi-connectivity convergence protocol (MCCP) stack entity, wherein the MCCP stack entity operates above respective radio access network protocol sub-stacks, and wherein the MCCP stack entity manages how UE data traffic is routed over the primary and secondary communication links.

11. The apparatus of claim 1, wherein operating above a respective radio access network protocol sub-stack comprises: operating above a Packet Data Convergence Protocol (PDCP) stack entity operating in each wireless communication link in the UE.

12. The apparatus of claim 1, wherein each wireless communication link operating in the UE comprises separate user plane and control plane stacks to provide independent operation from each other wireless communication link operating in the UE.

13. The apparatus of claim 1, wherein the one or more processors are further to provide PDCP bearer partitioning by the MCCP stack entity.

14. The apparatus of claim 10, wherein the MCCP stack entity comprises a user plane part MCCP-u and a control plane part MCCP-c.

15. An apparatus of a base station operable to communicate with a User Equipment (UE) on a wireless network, comprising:

one or more processors configured to:

selectively operating the base station in a first operating state to act as an anchor base station for at least one UE, wherein operating as the anchor base station comprises providing communication between the at least one UE and a core network serving the wireless network; and

selectively operating the base station in a second operational state to act as a booster base station for the at least one UE, wherein operating as the booster base station comprises providing communication between the at least one UE and a radio access network of the wireless network;

wherein the one or more processors are further to:

selecting between the first operating state and the second operating state based on information from the at least one UE.

16. The apparatus of claim 15, wherein the anchor base station provides user plane and control plane communications between the at least one UE and a core network.

17. The apparatus of claim 15, wherein the booster base station provides user plane and control plane communications between the at least one UE and the anchor base station.

18. The apparatus of claim 15, wherein the booster base station communicates with the anchor base station over a base station to base station communication link interface, optionally an X2 interface.

19. The apparatus of claim 15, wherein the base station provides at least two primary communication links with the at least one UE, and wherein the one or more processors are further configured to partition traffic to be transmitted between the at least two primary communication links.

20. The apparatus of claim 15, wherein the one or more processors are further configured to:

providing a multi-connectivity convergence protocol (MCCP) stack entity, wherein the MCCP stack entity operates above respective radio access network protocol sub-stacks, and wherein the MCCP stack entity manages how data traffic for the at least one UE is routed over the primary communication link and the secondary communication link.