WO2017034505A1 - Methods and apparatus for fast uplink access - Google Patents

Abstract

Methods and apparatuses for communicating in a wireless network include methods and apparatus to enable a UE to achieve low Radio Access Network (RAN) latency by expediting the UE initiated UL (Up Link) transmission, including an evolved NodeB (eNB) for use in a wireless communication network, the eNB comprising: a radio interface, control logic coupled to the radio interface, the control logic to: obtain data, received from a user equipment (UE) via the radio interface on a physical uplink shared channel (PUSCH), and process the received data, wherein the data is received without having received a scheduling request for uplink resources from the user equipment.

Description

METHODS AND APPARATUS FOR FAST UPLINK ACCESS

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional Patent Application No. 62/208,460, filed August 21, 2015, entitled "FAST UPLINK ACCESS SOLUTIONS FOR LATENCY REDUCTION" the entire disclosure of which is hereby incorporated by reference.

TECHNICAL FIELD

Embodiments described herein generally relate to the field of wireless communications and, more particularly but not exclusively to methods and apparatus for supporting low-latency uplink access in wireless communication networks.

BACKGROUND

It is becoming more important to be able to provide telecommunication services to fixed and mobile subscribers as efficient and inexpensively as possible. Further, the increased use of mobile applications has resulted in much focus on developing wireless systems capable of delivering large amounts of data at high speed.

Development of more efficient and higher bandwidth wireless networks has become increasingly important and addressing issues of how to maximize efficiencies in such networks is ongoing. One such issue relates to latency reduction of transmissions between a User Equipment (UE) and the network, both in the uplink and in the downlink. In particular, the reduction of user plane latency for scheduled uplink transmission is important to improve user experience.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects, features and advantages of embodiments of the present invention will become apparent from the following description of the invention in reference to the appended drawing in which like numerals denote like elements and in which:

Fig. 1 is block diagram of an example wireless network according to various embodiments;

Fig. 2 is a flow diagram showing an exemplary method for an eNB to determine and indicate support of fast uplink access using processing time reduction according to various embodiments;

Fig. 3 is a flow diagram showing an exemplary method for an UE supporting fast uplink access using processing time reduction according to various embodiments;

Fig. 4 is a flow diagram illustrating an exemplary method for an eNB for fast uplink access using preemptive scheduling of uplink resources according to various embodiments; Fig. 5 is a flow diagram illustrating an exemplary method for a UE for fast uplink access using preemptive scheduling of uplink resources according to various embodiments;

Fig. 6 is a flowchart illustrating a method performed by a UE according to various embodiments;

Fig. 7 is a timing diagram illustrating operation of a contention resolution timer according to various embodiments;

Fig. 8 is a block diagram of an example system operable to implement some embodiments; and

Fig. 9 is a block diagram showing an example wireless apparatus configured for communicating in a wireless network according to one or more of the inventive methods disclosed herein.

DETAILED DESCRIPTION

The following inventive embodiments may be used in a variety of applications including transmitters and receivers of a radio system, although the present invention is not limited in this respect. Radio systems specifically included within the scope of the present invention include, but are not limited to, network interface cards (NICs), network adaptors, fixed or mobile client devices, relays, base stations, femtocells, gateways, bridges, hubs, routers, access points, or other network devices. Further, the radio systems within the scope of the invention may be implemented in cellular radiotelephone systems, satellite systems, two-way radio systems as well as computing devices including such radio systems including personal computers (PCs), tablets and related peripherals, personal digital assistants (PDAs), personal computing accessories, handheld communication devices and all systems which may be related in nature and to which the principles of the inventive embodiments could be suitably applied.

Figure 1 schematically illustrates a wireless communication network 100 in accordance with various embodiments. Wireless communication network 100 (hereinafter "network 100") may be an access network of a 3rd Generation Partnership Project (3GPP) long-term evolution (LTE) or long-term evolution- advanced (LTE-A) network such as an evolved universal mobile telecommunication system (UMTS) terrestrial radio access network (E-UTRAN).

The network 100 may include a base station, e.g., evolved node base station (eNB) 104, configured to wirelessly communicate with one or more mobile device(s) or terminal(s), e.g., user equipment (UE) 108. In various embodiments, the eNB 104 may be a fixed station (e.g., a fixed node) or a mobile station/node.

The eNB 104 may include a receiver module 120 with which to receive signals from UE 108 via one or more antennas 130. eNB 104 may include a transmitter module 124 with which to transmit signals to UE 108 via one or more antennas 130. eNB 104 may also include a processor module 128 in communication with receiver module 120 and transmitter module 124 and configured to encode and decode information communicated by the signals. Processor module 128 also includes a low-latency uplink module 126 to facilitate low latency operation for low- latency capable UEs operating in the network 100.

In various embodiments, the UE 108 and/or the eNB 104 may include a plurality of antennas 156, 130 to implement a multiple-input-multiple-output (MIMO) transmission system, which may operate in a variety of MIMO modes, including single-user MIMO (SU-MIMO), multiuser MIMO (MU-MIMO), close loop MIMO, open loop MIMO or variations of smart antenna processing.

In various embodiments, UE 108 comprises a transmitter module 148 for transmitting signals to eNB 104 and a receiver module 144 for receiving signals from the eNB 104. UE 108 further comprises a processor module 152 coupled between a receiver module 144 and a transmitter module 148 and including a communication module 154 to encode and decode information communicated by the signals. Processor module 152 may also include low-latency uplink module 158 to facilitate low latency uplink operation by the UE 108.

While embodiments are described with reference to an LTE and/or LTE-A network, some embodiments may be used with other types of wireless access networks.

Embodiments herein may enable a UE to achieve low Radio Access Network (RAN) latency (also known as UP level latency, E2E latency or air interface latency) by expediting the UE initiated UL (Up Link) transmission.

According to some embodiments, uplink RAN latency may be reduced by reducing the scheduling request (SR) related delay.

According to some embodiments, the uplink RAN latency may be reduced by removing the SR transmission requirement by a UE wishing to initiate an uplink (UL) transmission.

In legacy LTE standards, for a UE wishing to initiate an UL transmission, and assuming that the UE is in connected mode/synchronized to the network (i.e., not requiring a random access (RACH) procedure), the UE waits for the next opportunity to send an scheduling request and then sends the scheduling request (SR) to the network. In response, the network transmits a scheduling grant allocating uplink resources for use by the UE. The UE then uses the granted resources for UL data transmission.

The communication of the scheduling request related elements may comprise a significant part in overall radio access network (RAN) latency. One approach to reduce or eliminate the SR related delay is to reduce the processing time required for processing scheduling requests by the network and the UE.

According to some embodiments, SR related delay may be reduced by the eNB processing the SR and sending an UL grant faster than the processing time assumed in UP delay analysis according to the legacy LTE standards, which is 3ms. In addition, further delay reduction may be achieved by reducing the processing time at the UE between the reception of UL grant and UL data transmission from that specified in the legacy specification, which is also 3ms.

While a certain reduction in processing time at the eNB and/or UE may be achieved through use of increased processing resources, selecting certain parameters to be used for the fast uplink transmission may facilitate further reductions. For example, according to some exemplary embodiments, one way to reduce processing delay in the UE would be to implement a TBS (Transport Block Size) restriction or fixed TBS for fast uplink transmission in order to reduce the required processing time between UL grant and UL data transmission.

Current LTE implementations may rely on a fixed timing for processing of scheduling requests, for example as noted above, the time between receipt of a SR at an eNB and transmission of a UL grant and the time between receipt of the UL grant at the UE and UL data transmission are defined as 3ms in the legacy LTE standards.

However, for a network implementing low latency UL transmission based on a reduction in processing time at UE and/or eNB, it may be necessary to define new timings between the UL grant to UL data transmission. For example, according to some embodiments, UL transmission on the Physical Uplink Shared Channel (PUSCH) may be changed to one of subframe (n+3) or (n+2) upon reception of the UL grant at subframe (n). It is noted that due to the timing alignment restrictions, it may not be possible to perform the PUSCH transmission in subframe (n+1) in normal scheduling, however, if slot-based scheduling is used, then the UL resources on the PUSCH may be scheduled in second slot of subframe (n+1) in some embodiments.

Further, the medium access control (MAC) protocol may need to be updated to reflect the new timings between the UL grant to UL data transmission.

For embodiments in which the processing times for the UL data transmission is reduced, this may result in a different hybrid automatic repeat request (HARQ) round trip time (RTT) compared to legacy values (for example, 8ms for FDD). This may require the number of supported HARQ processes to be changed. For example, if the UE and eNB processing delays are reduced to 2ms, then HARQ RTT may be 6ms for FDD resulting in a maximum number of supported HARQ processes being limited to 6 (for a TTI of 1ms). According to some embodiments, legacy devices and reduced uplink latency devices may coexist in the same network. In such cases, it may be necessary to signal the reduced processing times to those UEs capable of taking advantage of low-latency uplink operation. If TBS restriction is used for reducing processing time, then this (re)configuration signaling may be required at the R C layer or the maximum TBS supporting the reduced processing time may be defined in the specification. Alternatively, if a fixed TBS is used for the reduced processing time, it may be configured by the eNB via RRC signaling. This may be defined as new Information Element in legacy RRC signaling or as a new system information block (SIB).

An example SIB indicating the processing delay for low-latency UEs is provided below: ASN1START

SystemlnformationBlockTypeX-rl3 ::= SEQUENCE {

processingTimelnfo-rl3 SEQUENCE {

ueProcessingDelayGrantToUL-rl3 ENUMERATED {

sfl, sf2, sf3, sf4, sf5, sf6, sf7, spare}

}

}

-- ASN1STOP

The description of an example Information Element for use in signaling the reduced processing times to be used by a UE between UL grant reception and the actual resource allocation subframe on the PUSCH is shown below. The value of ueProcessingDelayGrantToUL may be more than sf3 (i.e. three subframes, which is current value for legacy UEs) if the TTI is reduced and the processing time could not be scaled by the same factor.

SystemlnformationBlockTypeX field description

ueProcessingDelayGrantToUL: indicates the allowed UE processing time between the UL grant reception and actual resource allocation subframe in the UL. The value is in subframes, sfl means 1 subframe, sf2 means 2 subframes and so on. The UL resources will be available in n+l+ueProcessingDelayGrantToUL subframe where n is current subframe.

An exemplary method 200 for communicating support for reduced latency in a wireless communication network 100 is shown in Figure 2. According to the described method, an eNB 104 may determine 202 that reduced support for UL latency is to be provided in the wireless network 100, or may be configured to provide such support to low-latency UEs 108 communicating with the eNB 104. The eNB 104 may then obtain 204 UL grant to UL data transmission timings to be used by low latency UEs 108. In one example, the eNB 104 may obtain value of such timing by enquiring/accessing the UE's processing capabilities using a separate method. In another example, the network may be pre-configured with such timing value to support fast UL access to capable UEs. The UL grant to UL data transmission timings may then be transmitted 206 to the UEs, for example as a system information block or information element as described above.

An exemplary method 300 that may be performed by low latency UE 108 is illustrated in Figure 3. According to method 300, the UE 108 first receives 302 an indication of UL grant to UL data transmission timings to be used for low latency UL operation for communication with the network. The UE 108 then adjusts 304 the number of subframes to be used between receiving an UL grant and transmitting UL data during operation of the UE 108 based on the received indication.

In some embodiments, the eNB 104 may further provide an indication of a transmission block size limitation, or a specific transmission block size, to be used in the UL by the low latency UE 108 to limit the processing to be performed at the UE facilitating the reduced time between the UE 108 receiving the UL grant and transmitting UL data during low latency operation.

According to some embodiments, delays associated with the signaling of scheduling requests and uplink grants may be avoided through the use of UL transmission by user equipment without first transmitting a scheduling request (SR) or buffer status report (BSR) information. Thus, in order to reduce or eliminate the SR/BSR transmission related delays, an eNB 104 may schedule a UE 108 and provide UL resource grants without requiring the UE 108 to send SR/BSR. According to some embodiments, this may be achieved in a number of different ways:

Dedicated Grants: The UL resource grants may be dedicated to each UE 108. However, dedicated grants for each UE, sent by the eNB 104 without the knowledge of UE's buffer status, may result in underutilization/wastage of resources if the UE does not have UL data to transmit in a received UL resource grant.

Shared Grants: The same UL grant may be shared by a group of UEs. However, a collision may happen if more than one UE 108 is transmitting uplink data using the same UL resource.

Contention PUSCH using RC configuration: Contention-based UL shared channels may be configured using RRC messaging. In this case, a collision may happen if more than one UE is transmitting using the same UL resource. This will not only remove the requirement to transmit SR/BSR, but also removes the need for an eNB 104 to provide UL grant messages. Figure 4 illustrates a method performed by an eNB 104 to enable low-latency uplink operation for UEs 108 based on the granting of uplink resources without requiring a UE 108 to first transmit a scheduling request. According to the method 400 of Figure 4, the eNB 104 determines 402 that low-latency UL access is to be supported for capable UEs 108 communicating with the eNB 104. Based on this determination, the eNB then preemptively schedules 404 UL resources for the low-latency capable UEs. This may be in the form of dedicated UL grants or shared UL grants as described above. The eNB 104 will then receive UL data on the preemptively scheduled UL resources without having received and processed scheduling requests from the UE 108 requesting UL resources for data transmission.

In the case of uplink channels being shared by more than one UE 108 (i.e. for shared grants and contention PUSCH using RRC configuration) HARQ performance may be degraded due to collisions in the absence of contention resolution mechanism. For example, for synchronous HARQ in the UL, when an eNB 104 sends a NACK, multiple UEs may perform HARQ retransmissions at the same time using the same UL resources resulting in repeated collisions. In addition, a new transmission may also collide with HARQ retransmissions.

A further potential issue may occur when an eNB 104 is able to decode one UL transmission among several contending UL transmissions and responds with an ACK. UEs other than the one whose transmission was successful may misinterpret the ACK as their own and will stop HARQ retransmission. Thus, the transmissions by the other UEs will fail and radio link control (RLC) retransmission will occur resulting in increased latency.

According to some embodiments, this may be avoided by providing an identifier of the UE 108 whose UL transmission is being ACKed with the ACK response. In order to allow the eNB 104 to include a UE identifier with the ACK, the UE 108 may include an identifier that is unique among the UEs communicating with the eNB 104 using the shared UL resources when transmitting the UL data.

Figure 5 illustrates a method 500 performed by a UE 108 when using shared UL resources for low-latency UL access. According to the method of Figure 5, the UE 108 first receives 502 an indication of shared UL resources scheduled on the PUSCH for contention based transmission. The UE 108 will then use the shared UL resources to transmit 504 UL data to the eNB 104, and will include a UE identifier with the data transmission.

According to some embodiments, for multiple UEs 108 that share the same allocated UL resources using contention based PUSCH transmission, a group UL grant may be introduced. The group grant may be a single UL grant which can be sent to a group of UEs. For embodiments implementing a group UL grant/shared UL grant solution, a group identifier may be introduced to send downlink control information (DCI) to a group of UEs. One example of group identifier may be a group radio network temporary identifier (RNTI).

In some embodiments, Physical Hybrid-ARQ Indicator Channel (PHICH) resource mapping may be modified to provide an indication HARQ-ACK to a particular transmitting UE in the group of UEs.

In some embodiments, radio resource control (RRC) (re)configuration may be used to create a UE group to share a common UL grant. Member addition, removal and update processes for group management may be defined.

In some embodiments, contention based PUSCH resources may be configured by RRC

(re)configuration signaling to the UEs. This may be achieved in a way similar to that used for semi-persistent scheduling (SPS) in which specific uplink resources may be configured for use by a UE 108 at a defined interval and on an ongoing basis. In particular, this approach may be used by the network to configure SPS-like resources for multiple UEs using the same UL resources. However, in contrast to the minimum periodicity of SPS defined in legacy standards of 10ms, the periodicity of the shared resources should be reduced to allow low latency access to be achieved.

When an eNB 104 allocates resources to a UE 108 without having received up-to-date BSR information, the UE may not have data to send although UL resource is allocated. According to the legacy LTE standards, even though no data is available to be transmitted, the UE would be expected to transmit padding bits and BSR in the allocated UL resources.

In the case of contention-based uplink transmission, it would not be possible to share the UL resources among multiple UEs if the UEs transmit in uplink even when their transmit buffer is empty. This is because there will be collision between transmitted data and padding bits transmitted from UEs with no data to transmit as soon as there are two or more UEs sharing the same UL resources.

In some embodiments, when the same UL resources are allocated to multiple UEs, when a UE has no data to transmit, the UE may ignore the allocated UL resource instead of sending padding bits and BSR, as illustrated in Figure 6. According to the method 600 of Figure 6, a UE 108 receiving 602 an uplink grant determines 604 whether it is configured for fast, or low-latency, uplink operation. If not, the UE proceeds 610 to form a MAC packet data unit (PDU) in the normal way for transmission on the granted resources. However, in the case that the UE is configured for fast uplink, the UE 108 then determines 606 whether the UL transmit buffer contains data. If it is determined that the transmit buffer is not empty, again the UE proceeds 610 to form a MAC PDU for transmission in the allocated resource. In the case that the UL transmit buffer is empty, the UE 108 will ignore 608 the granted resources, not transmitting any padding bits or BSR information as would be required according to the legacy standards. By not transmitting padding bits, collisions and interference in the uplink between UEs may be reduced and some power saving maybe achieved in the UEs.

In some embodiments, an RRC message may be provided to configure low-latency UEs to skip UL transmission when there is no data in the buffer.

In some embodiments, if a UE 108 is configured to be a low-latency UE, either by preconfiguration or by some other equivalent procedure such as enabling the UE 108 to have shared and/or group UL grants, it may decide to ignore the allocated UL resource when its transmit buffer is empty based on its configured status.

In some embodiments, when a UE's transmit buffer is non-empty, depending on allocated UL resources, the UE 108 may send BSR and/or data without sending SR.

As described above, according to some embodiments multiple UEs may be allocated the same UL resources (PUSCH) to transmit uplink data. In this case, collisions may happen in the UL when more than one UE attempts to transmit uplink data in the same UL resources. To mitigate the possibility of collisions, the following procedure for MAC layer contention resolution mechanism may be applied.

In some embodiments, a group comprising a plurality of UEs may share a group-grant. Each UE 108 in the plurality of UEs may transmit UL data using the allocated shared grant along with an individual ID associated with that UE. One example of such individual ID may be a C-RNTI and may be included in a MAC PDU. If an eNB 104 successfully receives and decodes an UL transmission, it may send an ACK in the DL including an indication of the transmitter's individual ID (e.g. an indication of C-RNTI using the physical downlink control channel (PDCCH)). The UE whose UL transmission has been successfully decoded by the eNB may determine, based on the individual ID associated with the ACK, that the ACK is for that UE. Other UEs who also transmitted using the same UL resources may determine based on the individual ID associated with the ACK that their UL transmissions were unsuccessful.

In some embodiments, it may be possible in certain circumstances for an eNB 104 to decode a transmitter's ID only, but not the data in an UL transmission. In this case, the eNB 104 may respond by transmitting a NACK indicating a transmitter UE's ID for the UE whose data is being NACKed. In that case, the transmitter UE 108 may then continue with the synchronous HARQ retransmission; all other UEs should then refrain from continuing with HARQ retransmission to avoid repeated collisions in the UL. The UE 108 receiving a NACK with its ID may use the same redundancy version or new redundancy version for HARQ retransmission. In some embodiments, to avoid a situation in which the UL transmissions from all UEs are lost, and hence neither ACK nor NACK is transmitted by eNB 104, or for the case in which the ACK/NACK is lost in the downlink, the transmitter UEs may use a contention resolution timer for each UL transmission.

Figure 7 illustrates the operation of a contention resolution timer according to some embodiments. As illustrated in Figure 7, a UE 108 may start 702a a contention resolution timer with every new transmission in the UL The timer may be stopped 704 when the UE gets an ACK or NACK for the transmitted PDU. The timer may then be restarted 702b if the UE retransmits the data in the UL. In the case that the UE does not receive an ACK or NACK and the timer expires 706, the UE may then proceed to resending the unsuccessful data using a contention management procedure as explained below.

In some embodiments, for a UE whose transmission is unsuccessful, the UE may reinitiate the UL transmission to resend the previously unsuccessful data. A maximum number of retransmissions that are allowed before the UE declares UL failure may be defined. In one embodiment, the UE may retransmit using the earliest UL resources that are available via the dedicated grant, or group grant or R C signaling.

In some embodiments, a UE can apply a random backoff before trying to retransmit in the UL. In some embodiments, a backoff parameter may be pre-defined or pre-configured. In some embodiments, the backoff parameter may be signaled via RRC. In some embodiments, the backoff parameter may be included in the ACK DL PDU. For example, a value of the backoff parameter may be determined based on traffic conditions or number of UEs in connected mode and being served by the eNB.

As used herein, the term "circuitry" or "logic" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules. In some embodiments, circuitry may include logic, at least partially operable in hardware.

Embodiments described herein may be implemented into a system using any suitably configured hardware and/or software. Figure 8 illustrates, for one embodiment, example components of an electronic device 800. In embodiments, the electronic device 800 may be a user equipment (UE), an evolved NodeB (eNB), or some other electronic device. In some embodiments, the electronic device 800 may include application circuitry 802, baseband circuitry 804, Radio Frequency (RF) circuitry 806, front-end module (FEM) circuitry 808 and one or more antennas 810, coupled together at least as shown.

The application circuitry 802 may include one or more application processors. For example, the application circuitry 802 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with and/or may 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 804 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 804 may include one or more baseband processors and/or control logic to process baseband signals received from a receive signal path of the RF circuitry 806 and to generate baseband signals for a transmit signal path of the RF circuitry 806. Baseband processing circuity 804 may interface with the application circuitry 802 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 806. For example, in some embodiments, the baseband circuitry 804 may include a second generation (2G) baseband processor 804a, third generation (3G) baseband processor 804b, fourth generation (4G) baseband processor 804c, and/or other baseband processor(s) 804d for other existing generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 804 (e.g., one or more of baseband processors 804a-d) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 806. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry 804 may include Fast-Fourier Transform (FFT), precoding, and/or constellation mapping/demapping functionality.

In some embodiments, encoding/decoding circuitry of the baseband circuitry 804 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 functionality are not limited to these examples and may include other suitable functionality in other embodiments.

In some embodiments, the baseband circuitry 804 may include elements of a protocol stack such as, for example, elements of an evolved universal terrestrial radio access network (EUT AN) protocol including, for example, physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and/or radio resource control (RRC) elements. A central processing unit (CPU) 804e of the baseband circuitry 804 may be configured to run elements of the protocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio digital signal processor(s) (DSP) 804f. The audio DSP(s) 804f may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments.

The baseband circuitry 804 may further include memory/storage 804g. The memory/storage 804g may be used to load and store data and/or instructions for operations performed by the processors of the baseband circuitry 804. Memory/storage for one embodiment may include any combination of suitable volatile memory and/or non-volatile memory. The memory/storage 804g may include any combination of various levels of memory/storage including, but not limited to, read-only memory (ROM) having embedded software instructions (e.g., firmware), random access memory (e.g., dynamic random access memory (DRAM)), cache, buffers, etc. The memory/storage 804g may be shared among the various processors or dedicated to particular processors.

Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 804 and the application circuitry 802 may be implemented together such as, for example, on a system on a chip (SOC).

In some embodiments, the baseband circuitry 804 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 804 may support communication with an evolved universal terrestrial radio access network (EUTRAN) and/or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 804 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

RF circuitry 806 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 806 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry 806 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 808 and provide baseband signals to the baseband circuitry 804. RF circuitry 806 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 804 and provide RF output signals to the FEM circuitry 808 for transmission.

In some embodiments, the RF circuitry 806 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 806 may include mixer circuitry 806a, amplifier circuitry 806b and filter circuitry 806c. The transmit signal path of the RF circuitry 806 may include filter circuitry 806c and mixer circuitry 806a. RF circuitry 806 may also include synthesizer circuitry 806d for synthesizing a frequency for use by the mixer circuitry 806a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 806a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 808 based on the synthesized frequency provided by synthesizer circuitry 806d. The amplifier circuitry 806b may be configured to amplify the down-converted signals and the filter circuitry 806c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 804 for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 806a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry 806a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 806d to generate RF output signals for the FEM circuitry 808. The baseband signals may be provided by the baseband circuitry 804 and may be filtered by filter circuitry 806c. The filter circuitry 806c 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 806a of the receive signal path and the mixer circuitry 806a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and/or upconversion respectively. In some embodiments, the mixer circuitry 806a of the receive signal path and the mixer circuitry 806a 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 circuitry 806a of the receive signal path and the mixer circuitry 806a may be arranged for direct downconversion and/or direct upconversion, respectively. In some embodiments, the mixer circuitry 806a of the receive signal path and the mixer circuitry 806a of the transmit signal path may be configured for super-heterodyne operation. In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry 806 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry 804 may include a digital baseband interface to communicate with the RF circuitry 806.

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

In some embodiments, the synthesizer circuitry 806d may be a fractional-N synthesizer or a fractional N/N+l synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 806d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

The synthesizer circuitry 806d may be configured to synthesize an output frequency for use by the mixer circuitry 806a of the RF circuitry 806 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 806d may be a fractional N/N+l synthesizer.

In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry 804 or the applications processor 802 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the applications processor 802.

Synthesizer circuitry 806d of the RF circuitry 806 may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus 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 either N or N+l (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the 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 break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle. In some embodiments, synthesizer circuitry 806d may be configured to generate a carrier frequency as the output frequency, while 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 used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry 806 may include an IQ/polar converter.

FEM circuitry 808 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 810, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 806 for further processing. FEM circuitry 808 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 806 for transmission by one or more of the one or more antennas 810.

In some embodiments, the FEM circuitry 808 may include a TX/RX switch to switch between transmit mode 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 received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 806). The transmit signal path of the FEM circuitry 808 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 806), and one or more filters to generate RF signals for subsequent transmission (e.g., by one br more of the one or more antennas 810.

In some embodiments, the electronic device 800 may include additional elements such as, for example, memory/storage, display, camera, sensor, and/or input/output (I/O) interface.

In some embodiments, the electronic device 800 may be configured to perform one or more processes, techniques, and/or methods as described herein, or portions thereof.

Figure 9 shows an embodiment in which the electronic device 800 implements a UE 108 in the specific form of a mobile device 900.

In various embodiments, user interfaces could include, but are not limited to, a display 940 (e.g., a liquid crystal display, a touch screen display, etc.), a speaker 930, a microphone 990, one or more cameras 980 (e.g., a still camera and/or a video camera), a flashlight (e.g., a light emitting diode flash), and a keyboard 970.

In various embodiments, the peripheral component interfaces may include, but are not limited to, a non-volatile memory port, an audio jack, and a power supply interface. In various embodiments, the sensors may include, but are not limited to, a gyro sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be part of, or interact with, a network interface to communicate with components of a positioning network, e.g., a global positioning system (GPS) satellite.

In various embodiments, the electronic device 800 may be a mobile computing device such as, but not limited to, a laptop computing device, a tablet computing device, a netbook, a mobile phone, etc. In various embodiments, system 900 may have more or less components, and/or different architectures.

In embodiments, the implemented wireless network may be a 3rd Generation Partnership Project's long term evolution (LTE) advanced wireless communication standard, which may include, but is not limited to releases 8, 9, 10, 11 and 12, or later, of the 3GPP's LTE-A standards.

EXAMPLES

Example 1 may comprise a network node such as eNB which is capable of handling low- latency UEs by enabling latency reduction functionalities.

Example 2 may comprise the network node of Example 1 or some other example herein, which is capable of signaling the low-latency UEs about the processing delay available from the grant reception to uplink data transmission.

Example 3 may comprise the network node of Example 1 or some other example herein, which is capable of signaling the low-latency UEs about the UL resource grants without getting SR request.

Example 4 may comprise the network node of Example 3 or some other example herein, where said UL grant can be provided to multiple UEs as a group grant for contention based access.

Example 5 may comprise the network node of Example 4 or some other example herein, which can respond to UL transmissions received from the UEs by corresponding ACK/NACK.

Example 6 may include that the ACK/NACK of Example 5, or some other example herein, is provided to UE using C-RNTI indication in PDCCH.

Example 7 may comprise a UE which is capable of receiving said RRC signaling of Example 2 (or some other example herein) from the network node such as eNB about the processing delay available to it and adjust its transmission timing between the UL grant reception and UL data transmission accordingly. Example 8 may comprise a UE which is capable of receiving said group grant of Example 4 (or some other example herein) and transmit its data on the allocated resource along with its individual ID.

Example 9 may include that the individual ID of Example 8, or some other example herein, is the C-RNTI.

Example 10 may comprise the UE of Example 8 or some other example herein, which can start/restart contention resolution timer with each new transmission and stop the timer when ACK/NACK of Example 5 (or some other example herein) is received.

Example 11 may comprise of the UE of Example 8 or some other example herein, which can perform a random backoff and initiate retransmission of data if ACK/NACK information of Example 5 (or some other example herein) is not received by it by the time the contention resolution timer of Example 10 (or some other example herein) is expired.

Example 12 may include an apparatus comprising means to perform one or more elements of a method described in or related to any of examples 1-11, or any other method or process described herein.

Example 13 may include one or more non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of a method described in or related to any of examples 1-11, or any other method or process described herein.

Example 14 may include an apparatus comprising logic, modules, and/or circuitry to perform one or more elements of a method described in or related to any of examples 1-11, or any other method or process described herein.

Example 15 may include a method, technique, or process as described in or related to any of examples 1-11, or portions or parts thereof.

Example 16 may include a method of communicating in a wireless network as shown and described herein.

Example 17 may include a system for providing wireless communication as shown and described herein.

Example 18 may include a device for providing wireless communication as shown and described herein.

Example 19 may include an apparatus for an evolved NodeB (eNB) for use in a wireless communication network, the apparatus comprising: a radio interface, control logic coupled to the radio interface, the control logic to: obtain data, received from a user equipment (UE) via the radio interface on a physical uplink shared channel (PUSCH), and process the received data, wherein the data is received without having received a scheduling request for uplink resources from the user equipment.

Example 20 may include the apparatus of example 19 the control logic further to provide a dedicated uplink grant for dedicated resources on the PUSCH to the user equipment without receiving a scheduling request from the user equipment.

Example 21 may include the apparatus of example 19 the control logic further to provide an indication of uplink shared resources to be used for contention-based uplink transmission on the PUSCH by a plurality of UEs.

Example 22 may include the apparatus of example 21 wherein the uplink shared resources are to be used by a plurality of UEs capable of contention-based uplink access connected to the eNB.

Example 23 may include the apparatus of example 21, the control logic further to provide an identification of a group comprising a plurality of UEs capable of contention based uplink access connected to the eNB, wherein the indicated uplink shared resources are for use by the identified group.

Example 24 may include the apparatus of any of examples 21 to 23, the control logic further to respond to the received data with a hybrid automatic repeat request (HARQ)- ACK/NACK, wherein the HARQ-ACK/NACK comprises an indication of a UE from which the data was received.

Example 25 may include a computer readable medium comprising computer program code to, when executed: obtain data, received from a user equipment (UE) via a radio interface on a physical uplink shared channel (PUSCH), and process the received data, wherein the data is received without having received a scheduling request for uplink resources from the UE.

Example 26 may include the computer readable medium of example 25 the program code further to provide an indication of uplink shared resources to be used for contention-based uplink transmission on the PUSCH by a plurality of UEs.

Example 27 may include an apparatus for a user equipment (UE) for use in a wireless communication network, the apparatus comprising: a radio interface, and control logic to: obtain, via the radio interface, an indication of shared uplink resources to be used for contention-based uplink transmission on a physical uplink shared channel (PUSCH) by a plurality of UEs, and generate a message comprising data for transmission on the indicated shared uplink resources via the radio interface. Example 28 may include the apparatus of example 27, wherein the generated message further comprises an identifier associated with the UE.

Example 29 may include the apparatus of example 28, wherein the identifier associated with the UE comprises a C-RNTI.

Example 30 may include the apparatus of any of examples 27 to 29, the control logic further to: determine whether the user equipment has data available to be transmitted, and in response to a determination that no data is available refraining from transmitting at least one of padding bits and a buffer status report in the indicated shared resources.

Example 31 may include the apparatus of any of examples 27 to 30, the control logic further to: receive, via the radio interface, a hybrid automatic repeat request (HARQ)-ACK/NACK comprising an identifier, determine whether the identifier is associated with the UE, and in response to a determination that the identifier is not associated with the user equipment disabling HARQ retransmission of the transmitted data.

Example 32 may include the apparatus of example 30, the control logic further to reschedule transmission of the transmitted data.

Example 33 may include the apparatus of any of examples 27 to 30, the control logic further to: determine that no HARQ-ACK/NACK has been received in response to the transmitted data within a predetermined period of time, and scheduling retransmission of the transmitted data.

Example 34 may include the apparatus of example 33, wherein scheduling retransmission of the transmitted data comprises scheduling retransmission using the next available uplink resources.

Example 35 may include the apparatus of example 33, wherein scheduling retransmission of the transmitted data comprises activating a random backoff timer and scheduling retransmission using the next available uplink resources after the random backoff timer expires.

Example 36 may include a computer readable medium comprising computer program code to, when executed on processing circuitry cause the processing circuitry to: obtain, an indication of shared uplink resources to be used for contention-based uplink transmission on the PUSCH by a plurality of user equipment (UEs), and generate a message comprising data for transmission on the indicated shared uplink resources.

Example 37 may include the computer readable medium of example 36, wherein the generated message further comprises an identifier associated with the UE.

Example 38 may include the computer readable medium of example 36, the program code further to cause the processing circuitry to: determine whether the user equipment has data available to be transmitted, and in response to a determination that no data is available refraining from transmitting at least one of padding bits and a buffer status report in the indicated shared resources.

Example 39 may include an apparatus for an eNB for use in a wireless communication network, the apparatus comprising: a radio interface, control logic coupled to the radio interface, the control logic to: obtain an indication of a number of subframes between an upload grant reception and a physical uplink shared channel (PUSCH) resource allocation for a user equipment (UE) capable of low-latency uplink operation in communication with the eNB, and cause the indication of the number of subframes to be transmitted via the radio interface.

Example 40 may include the apparatus of example 39, wherein the indication comprises an information element.

Example 41 may include the apparatus of example 39, wherein the indication comprises a system information block.

Example 42 may include the apparatus of any of examples 39 to 41, the control logic further to cause the radio interface to transmit an indication of a transport block size restriction to be applied in conjunction with the indicated number of subframes between an upload grant reception and a PUSCH resource allocation.

Example 43 may include an apparatus for a user equipment (UE) for use in a wireless communication network, the apparatus comprising: a radio interface, control logic coupled to the radio interface, the control logic to: receive, via the radio interface, an indication of a number of subframes between an upload grant reception and a physical uplink shared channel (PUSCH) resource allocation for a low-latency uplink mode of operation, and adjust a transmission timing between an uplink grant reception and uplink data transmission via the radio interface based on the received indication.

Example 44 may include the apparatus of example 43, the control logic further to receive an indication of a transport block size restriction and to encode data for the uplink data transmission based on the received transport block size restriction.

Example 45 may include a computer readable medium comprising computer program code to, when executed: provide an indication of a number of subframes between an upload grant reception and a physical uplink shared channel (PUSCH) resource allocation for a UE capable of low-latency uplink operation in communication with an eNB, and cause the indication of the number of subframes to be transmitted via a radio interface.

The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various implementations of the invention.

Claims

CLAIMS The invention claimed is:

1. An apparatus for an evolved NodeB (eNB) for use in a wireless communication network, the apparatus comprising:

a radio interface;

control logic coupled to the radio interface, the control logic to:

obtain data, received from a user equipment (UE) via the radio interface on a physical uplink shared channel (PUSCH); and

process the received data;

wherein the data is received without having received a scheduling request for uplink resources from the user equipment.

2. The apparatus of claim 1 the control logic further to provide a dedicated uplink grant for dedicated resources on the PUSCH to the user equipment without receiving a scheduling request from the user equipment.

3. The apparatus of claim 1 the control logic further to provide an indication of uplink shared resources to be used for contention-based uplink transmission on the PUSCH by a plurality of UEs.

4. The apparatus of claim 3 wherein the uplink shared resources are to be used by a plurality of UEs capable of contention-based uplink access connected to the eNB.

5. The apparatus of claim 3, the control logic further to provide an identification of a group comprising a plurality of UEs capable of contention based uplink access connected to the eNB; wherein the indicated uplink shared resources are for use by the identified group.

6. The apparatus of any of claims 3 to 5, the control logic further to respond to the received data with a hybrid automatic repeat request (HARQ)-ACK/NACK, wherein the HARQ-ACK/NACK comprises an indication of a UE from which the data was received.

7. A computer readable medium comprising computer program code to, when executed: obtain data, received from a user equipment (UE) via a radio interface on a physical uplink shared channel (PUSCH); and

process the received data;

wherein the data is received without having received a scheduling request for uplink resources from the UE.

8. The computer readable medium of claim 7 the program code further to provide an indication of uplink shared resources to be used for contention-based uplink transmission on the PUSCH by a plurality of UEs.

9. An apparatus for a user equipment (UE) for use in a wireless communication network, the apparatus comprising:

a radio interface;

control logic to:

obtain, via the radio interface, an indication of shared uplink resources to be used for contention-based uplink transmission on a physical uplink shared channel (PUSCH) by a plurality of UEs; and

generate a message comprising data for transmission on the indicated shared uplink resources via the radio interface.

10. The apparatus of claim 9, wherein the generated message further comprises an identifier associated with the UE.

11. The apparatus of claim 10, wherein the identifier associated with the UE comprises a cell radio network temporary identifier (C-RNTI).

12. The apparatus of any of claims 9 to 11, the control logic further to:

determine whether the user equipment has data available to be transmitted; and in response to a determination that no data is available refraining from transmitting at least one of padding bits and a buffer status report in the indicated shared resources.

13. The apparatus of any of claims 9 to 12, the control logic further to:

receive, via the radio interface, a hybrid automatic repeat request (HARQ)-ACK/NACK comprising an identifier;

determine whether the identifier is associated with the UE; and

in response to a determination that the identifier is not associated with the user equipment disabling HARQ retransmission of the transmitted data.

14. The apparatus of claim 13, the control logic further to reschedule transmission of the transmitted data.

15. The apparatus of claim 9 to 12, the control logic further to:

determine that no HARQ-ACK/NACK has been received in response to the transmitted data within a predetermined period of time; and

scheduling retransmission of the transmitted data.

16. The apparatus of claim 15, wherein scheduling retransmission of the transmitted data comprises scheduling retransmission using the next available uplink resources.

17. The apparatus of claim 15, wherein scheduling retransmission of the transmitted data comprises activating a random backoff timer and scheduling retransmission using the next available uplink resources after the random backoff timer expires.

18. A computer readable medium comprising computer program code to, when executed on processing circuitry cause the processing circuitry to:

obtain, an indication of shared uplink resources to be used for contention-based uplink transmission on the PUSCH by a plurality of user equipment (UEs); and

generate a message comprising data for transmission on the indicated shared uplink resources.

19. An apparatus for an eNB for use in a wireless communication network, the apparatus comprising:

a radio interface;

control logic coupled to the radio interface, the control logic to:

obtain an indication of a number of subframes between an upload grant reception and a physical uplink shared channel (PUSCH) resource allocation for a user equipment (UE) capable of low-latency uplink operation in communication with the eNB; and

cause the indication of the number of subframes to be transmitted via the radio interface.

20. The apparatus of claim 19, wherein the indication comprises an information element.

21. The apparatus of claim 19, wherein the indication comprises a system information block.

22. The apparatus of any of claims 19 to 21, the control logic further to cause the radio interface to transmit an indication of a transport block size restriction to be applied in conjunction with the indicated number of subframes between an upload grant reception and a PUSCH resource allocation.

23. An apparatus for a user equipment (UE) for use in a wireless communication network, the apparatus comprising:

a radio interface;

control logic coupled to the radio interface, the control logic to:

receive, via the radio interface, an indication of a number of subframes between an upload grant reception and a physical uplink shared channel (PUSCH) resource allocation for a low-latency uplink mode of operation; and

adjust a transmission timing between an uplink grant reception and uplink data transmission via the radio interface based on the received indication.

24. The apparatus of claim 23, the control logic further to receive an indication of a transport block size restriction and to encode data for the uplink data transmission based on the received transport block size restriction.

25. A computer readable medium comprising computer program code to, when executed: provide an indication of a number of subframes between an upload grant reception and a physical uplink shared channel (PUSCH) resource allocation for a UE capable of low-latency uplink operation in communication with an eNB; and

cause the indication of the number of subframes to be transmitted via a radio interface.