WO2014047933A1

WO2014047933A1 - Method and apparatus for rrc message combining

Info

Publication number: WO2014047933A1
Application number: PCT/CN2012/082469
Authority: WO
Inventors: Xipeng Zhu; Rohit Kapoor; Sharad Deepak Sambhwani; Francesco Pica; Bongyong Song; Ajay Gupta
Original assignee: Qualcomm Incorporated
Priority date: 2012-09-29
Filing date: 2012-09-29
Publication date: 2014-04-03
Also published as: WO2014048115A1

Abstract

Apparatus and methods are described herein for optimizing wireless communications using radio resource control (RRC) combining. An RRC request message includes a non-access stratum (NAS) service request. An RRC connection setup message can then be provided including a combination of information for configuring the RRC connection.

Description

METHOD AND APPARATUS FOR RRC MESSAGE COMBINING

BACKGROUND

Field

[0001] Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to optimizing data connections for small data transfer using RRC message combining.

Background

[0002] Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). The UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), and Time Division-Synchronous Code Division Multiple Access (TD- SCDMA). The UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSPA), which provides higher data transfer speeds and capacity to associated UMTS networks.

[0003] As the demand for mobile broadband access continues to increase, research and development continue to advance the UMTS technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 is a block diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

[0005] FIG. 2 is a block diagram conceptually illustrating an example of a telecommunications system. [0006] FIG. 3 is a conceptual diagram illustrating an example of an access network.

[0007] FIG. 4 is a conceptual diagram illustrating an example of a radio protocol architecture for the user and control plane.

[0008] FIG. 5 is a block diagram conceptually illustrating an example of a Node B in communication with a UE in a telecommunications system.

[0009] FIG. 6 depicts a typical data request procedure for data transmission in UMTS.

[0010] FIG. 7 depicts a data request procedure for data transmission in UMTS using

RRC combining.

[0011] FIG. 8 depicts a typical data request procedure for data transmission in LTE.

[0012] FIGs. 9A and 9B depict a data request procedure for data transmission in LTE using RRC combining.

[0013] FIG. 10 is a flowchart depicting a method for data connectivity using RRC combining.

[0014] FIG. 11 is a flowchart depicting another method for data connectivity using

RRC combining.

[0015] FIG. 12 is a block diagram conceptually illustrating a communication device employing RRC combining.

DETAILED DESCRIPTION

[0016] The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0017] FIG. 1 is a block diagram illustrating an example of a hardware implementation for an apparatus 100 employing a processing system 114. In this example, the processing system 114 may be implemented with a bus architecture, represented generally by the bus 102. The bus 102 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 114 and the overall design constraints. The bus 102 links together various circuits including one or more processors, represented generally by the processor 104, and computer- readable media, represented generally by the computer-readable medium 106. The bus 102 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. A bus interface 108 provides an interface between the bus 102 and a transceiver 110. The transceiver 110 provides a means for communicating with various other apparatus over a transmission medium. Depending upon the nature of the apparatus, a user interface 112 (e.g., keypad, display, speaker, microphone, joystick) may also be provided.

[0018] The processor 104 is responsible for managing the bus 102 and general processing, including the execution of software stored on the computer-readable medium 106. The software, when executed by the processor 104, causes the processing system 114 to perform the various functions described infra for any particular apparatus. The computer-readable medium 106 may also be used for storing data that is manipulated by the processor 104 when executing software.

[0019] The various concepts presented throughout this disclosure may be implemented across a broad variety of telecommunication systems, network architectures, and communication standards. By way of example and without limitation, the aspects of the present disclosure illustrated in FIG. 2 are presented with reference to a UMTS system 200 employing a W-CDMA air interface. A UMTS network includes three interacting domains: a Core Network (CN) 204, a UMTS Terrestrial Radio Access Network (UTRAN) 202, and User Equipment (UE) 210. In this example, the UTRAN 202 provides various wireless services including telephony, video, data, messaging, broadcasts, and/or other services. The UTRAN 202 may include a plurality of Radio Network Subsystems (RNSs) such as an RNS 207, each controlled by a respective Radio Network Controller (RNC) such as an RNC 206. Here, the UTRAN 202 may include any number of RNCs 206 and RNSs 207 in addition to the RNCs 206 and RNSs 207 illustrated herein. The RNC 206 is an apparatus responsible for, among other things, assigning, reconfiguring and releasing radio resources within the RNS 207. The RNC 206 may be interconnected to other RNCs (not shown) in the UTRAN 202 through various types of interfaces such as a direct physical connection, a virtual network, or the like, using any suitable transport network.

[0020] Communication between a UE 210 and a Node B 208 may be considered as including a physical (PHY) layer and a medium access control (MAC) layer. Further, communication between a UE 210 and an RNC 206 by way of a respective Node B 208 may be considered as including a radio resource control (RRC) layer. In the instant specification, the PHY layer may be considered layer 1; the MAC layer may be considered layer 2; and the RRC layer may be considered layer 3. Information hereinbelow utilizes terminology introduced in the RRC Protocol Specification, 3GPP TS 25.331 v9.1.0, incorporated herein by reference.

[0021] The geographic region covered by the RNS 207 may be divided into a number of cells, with a radio transceiver apparatus serving each cell. A radio transceiver apparatus is commonly referred to as a Node B in UMTS applications, but may also be referred to by those skilled in the art as a base station (BS), a base transceiver station (BTS), a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), an access point (AP), or some other suitable terminology. For clarity, three Node Bs 208 are shown in each RNS 207; however, the RNSs 207 may include any number of wireless Node Bs. The Node Bs 208 provide wireless access points to a CN 204 for any number of mobile apparatuses. Examples of a mobile apparatus include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a notebook, a netbook, a smartbook, a personal digital assistant (PDA), a satellite radio, a global positioning system (GPS) device, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, or any other similar functioning device. The mobile apparatus is commonly referred to as a UE in UMTS applications, but may also be referred to by those skilled in the art as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. In a UMTS system, the UE 210 may further include a universal subscriber identity module (USEVl) 211, which contains a user's subscription information to a network. For illustrative purposes, one UE 210 is shown in communication with a number of the Node Bs 208. The DL, also called the forward link, refers to the communication link from a Node B 208 to a UE 210, and the UL, also called the reverse link, refers to the communication link from a UE 210 to a Node B 208.

[0022] The CN 204 interfaces with one or more access networks, such as the UTRAN

202. As shown, the CN 204 is a GSM core network. However, as those skilled in the art will recognize, the various concepts presented throughout this disclosure may be implemented in a RAN, or other suitable access network, to provide UEs with access to types of CNs other than GSM networks.

[0023] The CN 204 includes a circuit-switched (CS) domain and a packet-switched (PS) domain. Some of the circuit- switched elements are a Mobile services Switching Centre (MSC), a Visitor location register (VLR) and a Gateway MSC. Packet-switched elements include a Serving GPRS Support Node (SGSN) and a Gateway GPRS Support Node (GGSN). Some network elements, like EIR, HLR, VLR and AuC may be shared by both of the circuit-switched and packet-switched domains. In the illustrated example, the CN 204 supports circuit- switched services with a MSC 212 and a GMSC 214. In some applications, the GMSC 214 may be referred to as a media gateway (MGW). One or more RNCs, such as the RNC 206, may be connected to the MSC 212. The MSC 212 is an apparatus that controls call setup, call routing, and UE mobility functions. The MSC 212 also includes a VLR that contains subscriber-related information for the duration that a UE is in the coverage area of the MSC 212. The GMSC 214 provides a gateway through the MSC 212 for the UE to access a circuit- switched network 216. The GMSC 214 includes a home location register (HLR) 215 containing subscriber data, such as the data reflecting the details of the services to which a particular user has subscribed. The HLR is also associated with an authentication center (AuC) that contains subscriber- specific authentication data. When a call is received for a particular UE, the GMSC 214 queries the HLR 215 to determine the UE's location and forwards the call to the particular MSC serving that location.

[0024] The CN 204 also supports packet-data services with a serving GPRS support node (SGSN) 218 and a gateway GPRS support node (GGSN)/serving gateway (SGW)/packet data network gateway (PGW) 220. GPRS, which stands for General Packet Radio Service, is designed to provide packet-data services at speeds higher than those available with standard circuit-switched data services. The GGSN/SGW/PGW 220 provides a connection for the UTRAN 202 to a packet-based network 222. The packet-based network 222 may be the Internet, a private data network, or some other suitable packet-based network. The primary function of the GGSN/SGW/PGW 220 is to provide the UEs 210 with packet-based network connectivity. Data packets may be transferred between the GGSN/SGW/PGW 220 and the UEs 210 through the SGSN 218, which performs primarily the same functions in the packet-based domain as the MSC 212 performs in the circuit- switched domain. [0025] An air interface for UMTS may utilize a spread spectrum Direct-Sequence Code

Division Multiple Access (DS-CDMA) system. The spread spectrum DS-CDMA spreads user data through multiplication by a sequence of pseudorandom bits called chips. The "wideband" W-CDMA air interface for UMTS is based on such direct sequence spread spectrum technology and additionally calls for a frequency division duplexing (FDD). FDD uses a different carrier frequency for the UL and DL between a Node B 208 and a UE 210. Another air interface for UMTS that utilizes DS-CDMA, and uses time division duplexing (TDD), is the TD-SCDMA air interface. Those skilled in the art will recognize that although various examples described herein may refer to a W-CDMA air interface, the underlying principles may be equally applicable to a TD- SCDMA air interface.

[0026] An HSPA air interface includes a series of enhancements to the 3G/W-CDMA air interface, facilitating greater throughput and reduced latency. Among other modifications over prior releases, HSPA utilizes hybrid automatic repeat request (HARQ), shared channel transmission, and adaptive modulation and coding. The standards that define HSPA include HSDPA (high speed downlink packet access) and HSUPA (high speed uplink packet access, also referred to as enhanced uplink, or EUL).

[0027] HSDPA utilizes as its transport channel the high-speed downlink shared channel

(HS-DSCH). The HS-DSCH is implemented by three physical channels: the high-speed physical downlink shared channel (HS-PDSCH), the high-speed shared control channel (HS-SCCH), and the high-speed dedicated physical control channel (HS-DPCCH).

[0028] Among these physical channels, the HS-DPCCH carries the HARQ

ACK/NACK signaling on the uplink to indicate whether a corresponding packet transmission was decoded successfully. That is, with respect to the downlink, the UE 210 provides feedback to the node B 208 over the HS-DPCCH to indicate whether it correctly decoded a packet on the downlink.

[0029] HS-DPCCH further includes feedback signaling from the UE 210 to assist the node B 208 in taking the right decision in terms of modulation and coding scheme and precoding weight selection, this feedback signaling including the CQI and PCI.

[0030] "HSPA Evolved" or HSPA+ is an evolution of the HSPA standard that includes

ΜΓΜΟ and 64-QAM, enabling increased throughput and higher performance. That is, in an aspect of the disclosure, the node B 208 and/or the UE 210 may have multiple antennas supporting MIMO technology. The use of MIMO technology enables the node B 208 to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity.

[0031] Multiple Input Multiple Output (MIMO) is a term generally used to refer to multi-antenna technology, that is, multiple transmit antennas (multiple inputs to the channel) and multiple receive antennas (multiple outputs from the channel). MIMO systems generally enhance data transmission performance, enabling diversity gains to reduce multipath fading and increase transmission quality, and spatial multiplexing gains to increase data throughput.

[0032] Spatial multiplexing may be used to transmit different streams of data simultaneously on the same frequency. The data steams may be transmitted to a single UE 210 to increase the data rate or to multiple UEs 210 to increase the overall system capacity. This is achieved by spatially precoding each data stream and then transmitting each spatially precoded stream through a different transmit antenna on the downlink. The spatially precoded data streams arrive at the UE(s) 210 with different spatial signatures, which enables each of the UE(s) 210 to recover the one or more the data streams destined for that UE 210. On the uplink, each UE 210 may transmit one or more spatially precoded data streams, which enables the node B 208 to identify the source of each spatially precoded data stream.

[0033] Spatial multiplexing may be used when channel conditions are good. When channel conditions are less favorable, beamforming may be used to focus the transmission energy in one or more directions, or to improve transmission based on characteristics of the channel. This may be achieved by spatially precoding a data stream for transmission through multiple antennas. To achieve good coverage at the edges of the cell, a single stream beamforming transmission may be used in combination with transmit diversity.

[0034] Generally, for MIMO systems utilizing n transmit antennas, n transport blocks may be transmitted simultaneously over the same carrier utilizing the same channelization code. Note that the different transport blocks sent over the n transmit antennas may have the same or different modulation and coding schemes from one another.

[0035] On the other hand, Single Input Multiple Output (SIMO) generally refers to a system utilizing a single transmit antenna (a single input to the channel) and multiple receive antennas (multiple outputs from the channel). Thus, in a SIMO system, a single transport block is sent over the respective carrier. [0036] Referring to Fig. 3, an access network 300 in a UTRAN architecture is illustrated. The multiple access wireless communication system includes multiple cellular regions (cells), including cells 302, 304, and 306, each of which may include one or more sectors. The multiple sectors can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell. For example, in cell 302, antenna groups 312, 314, and 316 may each correspond to a different sector. In cell 304, antenna groups 318, 320, and 322 each correspond to a different sector. In cell 306, antenna groups 324, 326, and 328 each correspond to a different sector. The cells 302, 304 and 306 may include several wireless communication devices, e.g., User Equipment or UEs, which may be in communication with one or more sectors of each cell 302, 304 or 306. For example, UEs 330 and 332 may be in communication with Node B 342, UEs 334 and 336 may be in communication with Node B 344, and UEs 338 and 340 can be in communication with Node B 346. Here, each Node B 342, 344, 346 is configured to provide an access point to a CN 204 (see FIG. 2) for all the UEs 330, 332, 334, 336, 338, 340 in the respective cells 302, 304, and 306.

[0037] As the UE 334 moves from the illustrated location in cell 304 into cell 306, a serving cell change (SCC) or handover may occur in which communication with the UE 334 transitions from the cell 304, which may be referred to as the source cell, to cell 306, which may be referred to as the target cell. Management of the handover procedure may take place at the UE 334, at the Node Bs corresponding to the respective cells, at a radio network controller 206 (see FIG. 2), or at another suitable node in the wireless network. For example, during a call with the source cell 304, or at any other time, the UE 334 may monitor various parameters of the source cell 304 as well as various parameters of neighboring cells such as cells 306 and 302. Further, depending on the quality of these parameters, the UE 334 may maintain communication with one or more of the neighboring cells. During this time, the UE 334 may maintain an Active Set, that is, a list of cells that the UE 334 is simultaneously connected to (i.e., the UTRA cells that are currently assigning a downlink dedicated physical channel DPCH or fractional downlink dedicated physical channel F-DPCH to the UE 334 may constitute the Active Set).

[0038] The modulation and multiple access scheme employed by the access network

300 may vary depending on the particular telecommunications standard being deployed. By way of example, the standard may include Evolution-Data Optimized (EV-DO) or Ultra Mobile Broadband (UMB). EV-DO and UMB are air interface standards promulgated by the 3rd Generation Partnership Project 2 (3GPP2) as part of the CDMA2000 family of standards and employs CDMA to provide broadband Internet access to mobile stations. The standard may alternately be Universal Terrestrial Radio Access (UTRA) employing Wideband-CDMA (W-CDMA) and other variants of CDMA, such as TD-SCDMA; Global System for Mobile Communications (GSM) employing TDM A; and Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDM employing OFDM A. UTRA, E-UTRA, UMTS, LTE, LTE Advanced, and GSM are described in documents from the 3GPP organization. CDMA2000 and UMB are described in documents from the 3GPP2 organization. The actual wireless communication standard and the multiple access technology employed will depend on the specific application and the overall design constraints imposed on the system.

[0039] The radio protocol architecture may take on various forms depending on the particular application. An example for an HSPA system will now be presented with reference to FIG. 4.

[0040] Referring to Fig. 4 an example radio protocol architecture 400 relates to the user plane 402 and the control plane 404 of a user equipment (UE) or node B/base station. For example, architecture 400 may be included in a UE such as a wireless device. The radio protocol architecture 400 for the UE and node B is shown with three layers: Layer 1 406, Layer 2 408, and Layer 3 410. Layer 1 406 is the lowest lower and implements various physical layer signal processing functions. As such, Layer 1 406 includes the physical layer 407. Layer 2 (L2 layer) 408 is above the physical layer 407 and is responsible for the link between the UE and node B over the physical layer 407. Layer 3 (L3 layer) 410 includes a radio resource control (RRC) sublayer 415. The RRC sublayer 415 handles the control plane signaling of Layer 3 between the UE and the UTRAN.

[0041] In the user plane, the L2 layer 408 includes a media access control (MAC) sublayer 409, a radio link control (RLC) sublayer 411, and a packet data convergence protocol (PDCP) 413 sublayer, which are terminated at the node B on the network side. Although not shown, the UE may have several upper layers above the L2 layer 408 including a network layer (e.g., IP layer) that is terminated at a PDN gateway on the network side, and an application layer that is terminated at the other end of the connection (e.g., far end UE, server, etc.). [0042] The PDCP sublayer 413 provides multiplexing between different radio bearers and logical channels. The PDCP sublayer 413 also provides header compression for upper layer data packets to reduce radio transmission overhead, security by ciphering the data packets, and handover support for UEs between node Bs. The RLC sublayer 411 provides segmentation and reassembly of upper layer data packets, retransmission of lost data packets, and reordering of data packets to compensate for out-of-order reception due to hybrid automatic repeat request (HARQ). The MAC sublayer 409 provides multiplexing between logical and transport channels. The MAC sublayer 409 is also responsible for allocating the various radio resources (e.g., resource blocks) in one cell among the UEs. The MAC sublayer 409 is also responsible for HARQ operations.

[0043] FIG. 5 is a block diagram of a Node B 510 in communication with a UE 550, where the Node B 510 may be the Node B 208 in FIG. 2, and the UE 550 may be the UE 210 in FIG. 2. In the downlink communication, a transmit processor 520 may receive data from a data source 512 and control signals from a controller/processor 540. The transmit processor 520 provides various signal processing functions for the data and control signals, as well as reference signals (e.g., pilot signals). For example, the transmit processor 520 may provide cyclic redundancy check (CRC) codes for error detection, coding and interleaving to facilitate forward error correction (FEC), mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM), and the like), spreading with orthogonal variable spreading factors (OVSF), and multiplying with scrambling codes to produce a series of symbols. Channel estimates from a channel processor 544 may be used by a controller/processor 540 to determine the coding, modulation, spreading, and/or scrambling schemes for the transmit processor 520. These channel estimates may be derived from a reference signal transmitted by the UE 550 or from feedback from the UE 550. The symbols generated by the transmit processor 520 are provided to a transmit frame processor 530 to create a frame structure. The transmit frame processor 530 creates this frame structure by multiplexing the symbols with information from the controller/processor 540, resulting in a series of frames. The frames are then provided to a transmitter 532, which provides various signal conditioning functions including amplifying, filtering, and modulating the frames onto a carrier for downlink transmission over the wireless medium through antenna 534. The antenna 534 may include one or more antennas, for example, including beam steering bidirectional adaptive antenna arrays or other similar beam technologies.

[0044] At the UE 550, a receiver 554 receives the downlink transmission through an antenna 552 and processes the transmission to recover the information modulated onto the carrier. The information recovered by the receiver 554 is provided to a receive frame processor 560, which parses each frame, and provides information from the frames to a channel processor 594 and the data, control, and reference signals to a receive processor 570. The receive processor 570 then performs the inverse of the processing performed by the transmit processor 520 in the Node B 510. More specifically, the receive processor 570 descrambles and despreads the symbols, and then determines the most likely signal constellation points transmitted by the Node B 510 based on the modulation scheme. These soft decisions may be based on channel estimates computed by the channel processor 594. The soft decisions are then decoded and deinterleaved to recover the data, control, and reference signals. The CRC codes are then checked to determine whether the frames were successfully decoded. The data carried by the successfully decoded frames will then be provided to a data sink 572, which represents applications running in the UE 550 and/or various user interfaces (e.g., display). Control signals carried by successfully decoded frames will be provided to a controller/processor 590. When frames are unsuccessfully decoded by the receiver processor 570, the controller/processor 590 may also use an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support retransmission requests for those frames.

[0045] In the uplink, data from a data source 578 and control signals from the controller/processor 590 are provided to a transmit processor 580. The data source 578 may represent applications running in the UE 550 and various user interfaces (e.g., keyboard). Similar to the functionality described in connection with the downlink transmission by the Node B 510, the transmit processor 580 provides various signal processing functions including CRC codes, coding and interleaving to facilitate FEC, mapping to signal constellations, spreading with OVSFs, and scrambling to produce a series of symbols. Channel estimates, derived by the channel processor 594 from a reference signal transmitted by the Node B 510 or from feedback contained in the midamble transmitted by the Node B 510, may be used to select the appropriate coding, modulation, spreading, and/or scrambling schemes. The symbols produced by the transmit processor 580 will be provided to a transmit frame processor 582 to create a frame structure. The transmit frame processor 582 creates this frame structure by multiplexing the symbols with information from the controller/processor 590, resulting in a series of frames. The frames are then provided to a transmitter 556, which provides various signal conditioning functions including amplification, filtering, and modulating the frames onto a carrier for uplink transmission over the wireless medium through the antenna 552.

[0046] The uplink transmission is processed at the Node B 510 in a manner similar to that described in connection with the receiver function at the UE 550. A receiver 535 receives the uplink transmission through the antenna 534 and processes the transmission to recover the information modulated onto the carrier. The information recovered by the receiver 535 is provided to a receive frame processor 536, which parses each frame, and provides information from the frames to the channel processor 544 and the data, control, and reference signals to a receive processor 538. The receive processor 538 performs the inverse of the processing performed by the transmit processor 580 in the UE 550. The data and control signals carried by the successfully decoded frames may then be provided to a data sink 539 and the controller/processor, respectively. If some of the frames were unsuccessfully decoded by the receive processor, the controller/processor 540 may also use an acknowledgement (ACK) and/or negative acknowledgement (NAC ) protocol to support retransmission requests for those frames.

[0047] The controller/processors 540 and 590 may be used to direct the operation at the

Node B 510 and the UE 550, respectively. For example, the controller/processors 540 and 590 may provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. The computer readable media of memories 542 and 592 may store data and software for the Node B 510 and the UE 550, respectively. A scheduler/processor 546 at the Node B 510 may be used to allocate resources to the UEs and schedule downlink and/or uplink transmissions for the UEs.

[0048] In a typical machine-to-machine (M2M) traffic pattern, a UE sends/receives only a small amount of data. Even though only a small amount of data is exchanged, the service request procedure for transitioning from idle to connected mode is a cause of much overhead for small data transmission. The apparatus and methods described herein seek to minimize the overhead by using RRC message combining for small data transmission optimization for UMTS and LTE. [0049] Figure 6 depicts a typical data request procedure for data transmission in UMTS.

Figure 6 shows communications among a UE 602, an RNC 604, an SGSN 606, and a GGSN/SGW/PGW 608. As shown at 612, the UE 602 and RNC 604 perform a random access procedure. The UE 602 and RNC 604 may then establish an RRC connection, as shown at 614. A non access stratum (NAS) service connection may then be established, as shown at 616. During this process, a NAS protocol data unit (PDU) is transmitted. Next, a security context is established, as shown at 618. A user plane connection may then be established, as shown at 620, including data radio bearer setup and Iu establishment. As shown in Figure 6, approximately 20 signaling message are required to setup an connection for transmitting data.

[0050] Turning now to Figure 7, an optimized data request procedure using RRC message combining for UMTS is shown. By combining NAS signaling, security, and radio bearer establishment into the RRC connection establishment procedure, overhead associated with establishing a data connection is reduced. Again, communications among a UE 702, an RNC 704, an SGSN 706, and a GGSN/SGW/PGW 708. As shown at 710, the UE begins in idle mode. As shown at 712, the UE 702 and RNC 704 perform a random access procedure. UE 702 may then transmit an RRC connection request to the RNC 704, as shown at 714. The RRC connection request may include a NAS PDU. Upon receipt of the RRC connection request, including the NAS PDU, RNC 704 may transmit a NAS service request to the SGSN 706, as shown at 716. The service request may include the network service access point identifier (NSAPI) of the MTC bearer.

[0051] The SGSN 706 may respond with a common ID, as shown at 718. The SGSN may also transmit a security mode command to the RNC, as shown at 720, concurrently with a radio access bearer (RAB) assignment request, as shown at 722. The RNC 704 then transmit an RRC connection setup message to the UE 702, as shown at 724. This message may include the signaling radio bearer (SRB), data radio bearer (DRB) for MTC, security mode command (SMC), and measurement control information. The UE 702 may respond with an RRC connection setup complete message, as shown at 726, include an SMC response, DRB establishment acknowledgment, and measurement acknowledgement. The RNC may then submit to the SGSN, a security mode response and RAB assignment response, as shown at 728, 730. The SGSN and the GGSN/SGW/PGW then update the PDP context, as shown at 732. [0052] RRC message combining can also be used to minimize overhead in LTE network communications. Figure 8 depicts a typical service request procedure for data transmission in LTE. Communications are shown among a UE 801, and eNodeB 803, an MME 805, an S-GW 807, and a P-GW 809. As shown at 810, an RRC connection procedure is performed between the UE 801 and the eNodeB 803. The eNodeB 803 then forwards a service request to the MME, as shown at 812. The MME responds with an initial context setup request, as shown at 814. This message provides information about configuring the UE to the eNodeB, including the S-GW address and uplink security context. The eNodeB and the UE then perform security configuration operations, as shown at 816. Next, the UE and the eNodeB may perform RRC connection reconfiguration in order to setup the data radio bearer, as shown at 818. Following setup of the DRB, the UE is able to transmit uplink small data packets, as shown at 819. The eNodeB may forward an initial context setup response to the MME, as shown at 820, data bearer modification may occur among the MME, S-GW, and P- GW, as shown at 822, and the downlink data packets can then be properly routed to the UE.

[0053] Figure 9 depicts a data connection setup using RRC message combining for LTE.

As shown in Figure 9, the number of messages required to establish a connection is reduced. As in Figure 8, communications are shown among a UE 901, and eNodeB 903, an MME 905, an S-GW 907, and a P-GW 909. As shown at 910, the UE may transmit an RRC Connection Request message the eNodeB. In contrast to the typical operation illustrated in Figure 8, this initial message from the UE to the eNodeB may include a service request. As shown at 912, a service request is forwarded from the eNodeB to the MME, which responds with an initial context setup request, shown at 914.

[0054] The eNodeB may then forward an RRC connection setup message to the UE, as shown at 916. This message may include information related to security context, measurement control, SRB, and DRB assignment. The UE may respond, as shown at 918, with an RRC connection setup complete message acknowledging all of the information provided in the RRC connection setup message by the eNodeB. As shown in Figure 9A, at least 4 RRC signaling message are saved using the novel RRC combining techniques described herein.

[0055] In some cases, the MME may reject the service request from the UE for various reasons (e.g., authentication failure, absence of UE context at MME, etc.). In this case, the MME may send a service reject message in response to the UE's service request as shown at 913 in Figure 9B. Once the eNodeB receives a Downlink NAS transport message (that includes a service reject in its NAS PDU) instead of the initial context setup request, it can detect MME's rejection of the UE's request. Therefore, it falls back to the normal RRC connection establishment procedure by configuring only SRB1 in the RRC connection setup without RRC combining, as shown at 915, 917. Once the SRB1 is established, the eNodeB forwards the NAS message (service reject) to the UE, as shown at 921. MME's request for releasing the UE context (UE context release command shown at 919) to eNodeB should be processed after delivering the service reject to the UE. Note that the MME is agnostic to the call flow optimizations between the UE and eNodeB illustrated in Figures 9A and 9B.

[0056] In general, small data packets require very short radio connections. Therefore, the connection can be quickly released once the small data transaction is completed. In LTE, the eNodeB makes a decision to release a connection and this is typically using a traffic inactivity timer which may not be efficient for small data packets. For this reason, a UE initiated connection release method can be introduced. A simple way is to introduce a "RRC connection release request" message that the UE can send to the eNodeB once it detects the end of a small data transmission (or after receiving the proper acknowledgement message).

[0057] Figure 10 is a flowchart illustrating an example of a method for optimizing data connectivity by using RRC combining. The method shown in Figure 10 may be performed, for example, by a UE, such as UE 702 or UE 901. As shown at 1002, the UE may transmit an RRC request message to initiate a data connection. The RRC request message includes a service request. For example, in the case of a UMTS network, the service request may include a Non-Access Stratum (NAS) protocol data unit (PDU). In the case of a LTE network, the service request may include, for example, a NAS service request message.

[0058] As shown at 1004, the UE may receive an RRC connection setup message information for configuring the RRC connection. For example, the RRC connection setup message may include NAS securing signaling information, data radio bearer establishment parameters, measurement control parameters, and/or other parameters. As shown at 1006, the UE may transmit an RRC connection setup completion message acknowledging the setup information.

[0059] Figure 11 depicts another example of a method for optimizing data connectivity by using RRC combining. The method shown in Figure 11 may be performed, for example, by a network entity, such as an RNC or an eNodeB. As shown at 1102, the network entity may receive an RRC connection request from a UE, for example. The request may include a service request, such as a NAS PDU or other NAS service request message. Upon request of the RRC connection request, the network entity may forward the service request to an upstream network entity, as shown at 1104. For example, in the case of a UMTS network, the service request may be forwarded to an SGSN. In the case of an LTE network, the service request may be forwarded to an MME.

[0060] The network entity may receive one or more parameters for configuring the UE, as shown at 1106. For example, in the case of an UMTS network, an RNC may receive a common identifier, a security code command, a radio access bearer assignment request, and/or other parameters. In the case of an LTE network, for example, an eNodeB may receive parameters such as the address of the networks S-GW, security context information, etc. Upon receipt of the parameters, the network entity may transmit an RRC connection setup message to the UE, providing parameters for establishing a data connection, as shown at 1108. For example, the RRC connection setup message may include SRB, DRB, security context, measurement control, and/or other parameters. As shown at 1108, the network entity receives an RRC connection setup complete message from the UE, indicating that the setup is complete.

[0061] Figure 12 is a functional block diagram of a communication device configured to implement RRC message combining. Communication device 1200 may be, for example, a UE, RNC, or eNodeB. Communication device 1200 includes a processor 1202 for carrying out processing functions associated with one or more of components and functions described herein. Processor 1202 can include a single or multiple set of processors or multi-core processors. Moreover, processor 1202 can be implemented as an integrated processing system and/or a distributed processing system.

[0062] Communication device 1200 further includes a memory 1204, such as for storing data used herein and/or local versions of applications being executed by processor 1202. Memory 1204 can include any type of memory usable by a computer, such as random access memory (RAM), read only memory (ROM), tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof.

[0063] Further, communication device 1200 includes a communications component

1206 that provides for establishing and maintaining communications with one or more entities utilizing hardware, software, and services as described herein. Communications component 1206 may carry communications between components on communication device 1200, as well as between communication device 1200 and external devices, such as devices located across a communications network and/or devices serially or locally connected to communication device 1200. For example, communications component 1206 may include one or more buses, and may further include transmit chain components and receive chain components associated with one or more transmitters and receivers, respectively, or one or more transceivers, operable for interfacing with external devices. For example, the communications component 1206 may receive signals to be processed using the optimized maximal ratio combining techniques.

[0064] Additionally, communication device 1200 may further include a data store 1208, which can be any suitable combination of hardware and/or software, that provides for mass storage of information, databases, and programs employed in connection with aspects described herein. For example, data store 1208 may be a data repository for applications not currently being executed by processor 1202.

[0065] Communication device 1200 may additionally include a user interface component 1210 operable to receive inputs from a user of communication device 1200, and further operable to generate outputs for presentation to the user. User interface component 1210 may include one or more input devices, including but not limited to a keyboard, a number pad, a mouse, a touch-sensitive display, a navigation key, a function key, a microphone, a voice recognition component, any other mechanism capable of receiving an input from a user, or any combination thereof. Further, user interface component 1210 may include one or more output devices, including but not limited to a display, a speaker, a haptic feedback mechanism, a printer, any other mechanism capable of presenting an output to a user, or any combination thereof.

[0066] Communication device 1200 may also include an optimized RRC connection management component 1212 configured to optimize the service request procedure. RRC connection management component 1212 may be configured to implement the features described above with respect to Figures 7 and 9-11.

[0067] Several aspects of a telecommunications system have been presented with reference to a W-CDMA system. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures and communication standards.

[0068] By way of example, various aspects may be extended to other UMTS systems such as TD-SCDMA, High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), High Speed Packet Access Plus (HSPA+) and TD- CDMA. Various aspects may also be extended to systems employing Long Term Evolution (LTE) (in FDD, TDD, or both modes), LTE-Advanced (LTE-A) (in FDD, TDD, or both modes), CDMA2000, Evolution-Data Optimized (EV-DO), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra- Wideband (UWB), Bluetooth, and/or other suitable systems. The actual telecommunication standard, network architecture, and/or communication standard employed will depend on the specific application and the overall design constraints imposed on the system.

In accordance with various aspects of the disclosure, an element, or any portion of an element, or any combination of elements may be implemented with a "processing system" that includes one or more processors. Examples of processors include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on a computer-readable medium. The computer-readable medium may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip), an optical disk (e.g., compact disk (CD), digital versatile disk (DVD)), a smart card, a flash memory device (e.g., card, stick, key drive), random access memory (RAM), read only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium may also include, by way of example, a carrier wave, a transmission line, and any other suitable medium for transmitting software and/or instructions that may be accessed and read by a computer. The computer-readable medium may be resident in the processing system, external to the processing system, or distributed across multiple entities including the processing system. The computer- readable medium may be embodied in a computer-program product. By way of example, a computer-program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

[0070] It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein.

[0071] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more." Unless specifically stated otherwise, the term "some" refers to one or more. A phrase referring to "at least one of a list of items refers to any combination of those items, including single members. As an example, "at least one of: a, b, or c" is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112, sixth paragraph, unless the element is expressly recited using the phrase "means for" or, in the case of a method claim, the element is recited using the phrase "step for."

Claims

CLAIMS What is claimed is:

1. A method of wireless communication in a wireless communication network, comprising:

transmitting a radio resource control (RRC) request message, the RRC request message including a non-access stratum service request;

receiving an RRC connection setup message comprising information for configuring an RRC connection; and

transmitting an RRC connection setup completion message acknowledging the instructions for configuring the RRC connection.

2. The method of claim 1, wherein the information for configuring the RRC connection includes, security information, data radio bearer configuration information, and measurement control information.

3. The method of claim 1, wherein the wireless communication network is a UMTS network.

4. The method of claim 1, wherein the wireless communication network is an LTE network.

5. A computer program product, comprising:

a computer-readable medium, including:

at least one instruction for causing a computer to transmit a radio resource control (RRC) request message, the RRC request message including a non-access stratum service request;

at least one instruction for causing the computer to receive an RRC connection setup message comprising information for configuring an RRC connection; and

at least one computer for causing the computer to transmit an RRC connection setup completion message acknowledging the instructions for configuring the RRC connection.

6. The computer program product of claim 5, further comprising at least one instruction for causing the computer to perform the method of any of claims 2-4.

7. An apparatus comprising:

means for transmitting a radio resource control (RRC) request message, the RRC request message including a non-access stratum service request;

means for receiving an RRC connection setup message comprising information for configuring an RRC connection; and

means for transmitting an RRC connection setup completion message acknowledging the instructions for configuring the RRC connection.

8. The apparatus of claim 7, further comprising:

at least one means for performing the method of any of claims 2-4.

9. An apparatus, comprising:

a memory storing computer-readable instructions for:

transmitting an RRC connection setup completion message acknowledging the instructions for configuring the RRC connection; and

a processor in communication with the memory and configured to execute the instructions.

10. The apparatus of claim 9, wherein the memory further comprises at least one instruction for performing the method of any of claims 2-4.

11. A method of wireless communication in a wireless communication network, comprising:

receiving an RRC connection request, the RRC connection request including a NAS service request;

forwarding the service request to an upstream network entity;

receiving one or more parameters for configuring a user equipment (UE); transmitting an RRC connection setup message to the UE providing parameters for establishing a data connection.