KR101600260B1 - Activating and deactivating semi-persistent scheduling for an lte voip radio bearer - Google Patents

Abstract

Methods, apparatus, and computer program products for wireless communication are provided. The apparatus may determine the operational state of the header compressor or header decompressor by determining a switch between different operating states associated with the header compressor and / or by switching between different operating states associated with the header decompressor . The persistent scheduling mode changes in response to changes in the operating state of the header compressor. The persistent scheduling mode may be enabled by activating uplink persistent scheduling when the operating state of the header compressor changes from the primary state to the secondary state and / or by activating the uplink persistent scheduling when the operating state of the header compressor exits from the secondary state. May be changed by deactivating persistent scheduling.

Description

[0001] ACTIVATING AND DEACTIVATING SEMI-PERSISTENT SCHEDULING FOR AN LTE VOIP RADIO BEARER [0002]

Cross-reference to related application (s)

[0002] This application is related to the subject matter of the present application, entitled " ACTIVATING AND DEACTIVATING SEMI-PERSISTENT SCHEDULING FOR AN ANTI-VOIP RADIO BEARER, " filed October 3, 2011 which is assigned to the assignee hereof and whose contents are hereby expressly incorporated by reference in their entirety. U.S. Provisional Application No. 61 / 542,713, entitled " ACTIVATING AND DEACTIVATING SEMI-PERSISTENT SCHEDULING FOR ANTI-VOIP RADIO BEARER, " filed on October 2, 2012, Which is expressly incorporated herein by reference in its entirety.

Field

This disclosure relates generally to communication systems and, more particularly, to enabling semi-persistent scheduling for VoIP services in LTE and High Speed Packet Access (HSPA) networks. And deactivating the same.

Wireless communication systems are widely used to provide various communication services such as voice, data, broadcast, and others. These communication systems may be multi-access systems that support simultaneous resource utilization by multiple users. This resource sharing is achieved through the use of shared system resources including bandwidth and transmit power. A number of multiple access systems are currently in use and may be used in various applications such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA) And orthogonal frequency division multiple access (OFDMA). These access systems may be used in conjunction with various communication standards such as those published by 3G Long Term Evolution (3GPP LTE). LTE is a new emerging communications standard and is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard, as published by the 3GPP. LTE improves spectrum efficiency to better support mobile broadband Internet access, lower costs, improve services, take advantage of new spectrum, and provide OFDMA, uplink (UL) on downlink (DL) (SC-FDMA), and multiple-input multiple-output (MIMO) antenna technology on a single carrier frequency division multiple access (OFDMA)

Wireless multiple-access communication systems typically support multiple wireless terminals. Each wireless terminal, also known as a mobile device or user equipment (UE), communicates with one or more base stations using forward and reverse links. The forward link refers to the communication link from the base stations to the mobile terminals or UEs, and may also be known as the downlink. The reverse link refers to the communication link from the UEs to the base stations (BSs). The communication link may be established by a single link system or a MIMO system.

The traffic generated by the UEs and BSs is partially managed by a serving network controller acting as an arbiter of wireless traffic. The network controller sends control information to the UEs, allocates radio resources to the UEs, manages uplink and downlink interference, and coordinates MIMO transmissions between neighboring BSs. The serving network controller acts as a central planner for managing heterogeneous wireless communications and ensures consistency and reliability.

One communication standard, 3GPP, is Semi-Persistent Scheduling (SPS), which eliminates the need for a Physical Downlink Control Channel (PDCCH) resource for each uplink and downlink resource grant, As well as a mechanism known as < RTI ID = 0.0 > When there are a large number of voice over internet protocol (VOIP) users, overhead is a limiting factor for efficient system operation. The 3GPP specification does not define activation and deactivation that triggers the mechanism for SPS, nor does it specify the conditions of SPS activation and deactivation. There is a need in the art for a method and apparatus for determining when to activate and deactivate uplink SPS for both the uplink and downlink to an LTE VoIP radio bearer based on the state of the eNB ROHC decompressor and the compressor There is a need.

In an aspect of the present disclosure, a method, a computer program product, and an apparatus are provided. The operating state of the header compressor or the header decompressor is determined. The operating state of the header compressor or the header decompressor may be determined by determining a transition between different operating states associated with the header compressor.

In some embodiments, the method includes varying the persistent scheduling mode in response to a change in the operating state of the header compressor. Changing the persistent scheduling mode may include activating uplink persistent scheduling when the operating state of the header compressor changes from a primary state to a secondary state. The step of changing the persistent scheduling mode may include deactivating uplink persistent scheduling when the operating state of the header compressor exits from the secondary state.

Determining the operational state of the header compressor or the header decompressor may include determining a transition between different operational states associated with the header decompressor. Changing the persistent scheduling mode may include activating downlink persistent scheduling when the operational state of the header decompressor changes from a static context state to a full context state . The step of changing the persistent scheduling mode may include deactivating the downlink persistent scheduling mode when the operating state of the header decompressor enters a no context state. The persistent scheduling mode may be changed during a talk period, where the talk period corresponds to the generation of a speech frame by the codec. The persistent scheduling mode may change when a silence descriptor is generated by the codec.

The step of changing the persistent scheduling mode may include activating the persistent scheduling mode. Activating the persistent scheduling mode may include determining a fixed set of recurring resource blocks, and determining the periodicity of the persistent scheduling mode. The step of changing the persistent scheduling mode may include deactivating the persistent scheduling mode. Deactivating the persistent scheduling mode may include deallocating a fixed set of repeated resource blocks when the packet size is larger or smaller than the fixed set of repeated resource blocks and the periodicity of the allocation changes.

The fixed set of repeated resource blocks may be modified when the packet size is larger or smaller than a fixed set of repeated resource blocks and the periodicity of allocation changes. In some embodiments, only the uplink resource blocks are deallocated. In some embodiments, only downlink resource blocks are deallocated.

The data generated by the codec or dual tone multi-function events may be communicated using a fixed set of repeated resource blocks. Semi-persistent scheduling may be deactivated after a conference call is established. By disabling uplink semi-persistent scheduling when speech frames are being received before the conference call is established, semi-persistent scheduling may be deactivated after the conference call is established. The possibility that semi-persistent scheduling may be deactivated after a conference call is established includes disabling downlink semi-persistent scheduling when speech frames are being transmitted before the conference call is established.

1 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.
2 is a diagram of a wireless peer-to-peer communication system.
3 is a diagram illustrating an example of a network architecture.
4 is a diagram illustrating an example of an access network.
5 is a diagram illustrating an example of a frame structure for use in an access network.
6 illustrates an exemplary format for UL in LTE.
7 is a diagram for illustrating an example of a wireless protocol architecture for a user and a control plane.
Figure 8 is a diagram illustrating an example of evolved Node B and user equipment in an access network.
9 is an exemplary view illustrating characteristics of a voice service using an AMR speech codec.
10 illustrates a process of ROHC O-mode applied to LTE VoIP on the uplink during AMR speech codec "talk period " according to an embodiment.
11 is a flowchart of a method for an uplink SPS activation algorithm for LTE VoIP.
12 is a flowchart of another method for an uplink SPS activation algorithm for LTE VoIP.
Figure 13 is a flowchart of a method for a downlink SPS activation algorithm for LTE VoIP.
14 is a flowchart of another method for a downlink SPS activation algorithm for LTE VoIP.
Figure 15 shows a user plane architecture with RIM.
Figure 16 illustrates a multi-party call in accordance with an embodiment of the present invention.
FIG. 17 illustrates an eNB user plane architecture with RIM (two traffic flows each including one payload type).
Figure 18 illustrates an eNB user plane architecture with RIM (one traffic flow comprising two payload types).

The following detailed description with reference to the accompanying drawings is intended as a description of various configurations and is not intended to represent only those 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 these concepts.

Some aspects of communication systems will now be presented with reference to various apparatus and methods. These devices and methods will be described in the following detailed description and refer to various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements" Will be illustrated in the accompanying drawings. These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

For example, an element, or any portion of an element, or any combination of elements, may be implemented as 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), and the like, configured to perform the various functionality described throughout this disclosure. State machines, gated logic, discrete hardware circuits, and other suitable hardware. One or more processors in the processing system may execute software. The software may be in the form of software, firmware, middleware, microcode, hardware description language, or otherwise referred to as instructions, instruction sets, code, code segments, program code, programs, subprograms, Is broadly construed to mean software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, will be. The software may reside on a computer readable medium. The computer readable medium may be a non-transitory computer readable medium. Non-transitory computer readable media include, for example, magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips) for storing software and / or instructions that may be accessed and read by a computer, But are not limited to, optical disks (e.g., compact disk (CD), digital versatile disk (DVD)), smart cards, flash memory devices (e.g., (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, and any other suitable medium. The computer-readable medium may reside within a processing system, be external to the processing system, or be distributed across a plurality of entities including a processing system. The computer-readable medium may be embodied as a computer-program product. For example, the computer-program product may include a computer-readable medium within the packaging material.

Thus, in one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored or encoded on a computer-readable medium as one or more instructions or code. Computer readable media include computer storage media. The storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, RAM, ROM, RAM, RAM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium. Disks and discs as used herein include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVD), floppy discs and Blu-ray discs, discs usually reproduce data magnetically, while discs reproduce data optically with a laser. Combinations of the above should also be included within the scope of computer readable media. Those skilled in the art will recognize how to optimally implement the described functionality presented throughout this disclosure, depending upon the overall design constraints imposed on the overall system and the particular application.

1 is a conceptual diagram illustrating an example of a hardware implementation for an apparatus 100 employing a processing system 114. As shown in FIG. The processing system 114 may be implemented with a bus architecture generally indicated by bus 102. The bus 102 may include any number of interconnect busses and bridges depending on the overall design constraints and the particular application of the processing system 114. [ The bus 102 may include various circuits, including one or more processors and / or hardware modules generally represented by the processor 104, and computer readable media generally represented 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 will not be described any further. Bus interface 108 provides an interface between bus 102 and transceiver 110. The transceiver 110 provides a means for communicating with various other devices on a transmission medium.

The processor 104 is responsible for general processing, including the management of the bus 102 and 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 below for any particular device. The computer readable medium 106 may also be used to store data operated by the processor 104 when executing the software.

FIG. 2 is a diagram of an exemplary peer-to-peer communication system 200. FIG. The peer-to-peer communication system 200 includes a plurality of wireless devices 206, 208, 210, 212. The peer-to-peer communication system 200 may overlap a cellular communication system, such as, for example, a wireless wide area network (WWAN). Some of the wireless devices 206, 208, 210, and 212 may communicate together in a peer-to-peer communication, some may communicate with the base station 204, and some may do both. For example, as shown in FIG. 2, the wireless devices 206 and 208 are in a peer-to-peer communication state and the wireless devices 210 and 212 are in a peer-to-peer communication state. The wireless device 212 is also in communication with the base station 204.

A wireless device may be implemented by a person of ordinary skill in the art as a user equipment, mobile station, subscriber station, mobile unit, subscriber unit, wireless unit, wireless node, remote unit, mobile device, wireless communication device, remote device, A mobile terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable term. The base station may be implemented by one of ordinary skill in the art as an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) an extended service set (ESS), a Node B, an evolved Node B, or some other appropriate term.

Exemplary methods and devices discussed below may be implemented in a variety of wireless peer-to-peer communication systems, such as, for example, WiFi based wireless peer-to-peer communication systems based on FlashLinQ, WiMedia, Bluetooth, ZigBee, Peer communication systems. The techniques described herein may be used inter alia in code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (SC-FDMA) networks. CDMA networks may implement wireless technologies such as Universal Terrestrial Radio Access (UTRA), CDMA2000, and other technologies. UTRA includes Wideband CDMA (W-CDMA) and Low Chip Rate (LCR). CDMA2000 covers IS-2000, IS-95, and IS-856 standards. A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM). OFDMA networks can implement wireless technologies such as evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, Flash-OFDM®, and others. UTRA, E-UTRA, and GSM are part of the Universal Mobile Telecommunications System (UMTS). LTE (Long Term Evolution) is a release of UMTS using E-UTRA. UTRA, E-UTRA, GSM, UMTS, and LTE are described in the specifications issued by the "3rd Generation Partnership Project" (3GPP). CDMA2000 is described within specifications published by "3rd Generation Partnership Project 2" (3GPP2). However, those skilled in the art will appreciate that the exemplary methods and apparatus are more generally applicable to various other wireless peer-to-peer communication systems.

FIG. 3 is a diagram illustrating an LTE network architecture 300 employing various devices 100 (see FIG. 1). The LTE network architecture 300 may be referred to as an Evolved Packet System (EPS) EPS 300 includes at least one user equipment (UE) 302, an evolved UMTS terrestrial radio access network (E-UTRAN) 304, an evolved packet core (EPC) 310, A Subscriber Server (HSS) 320, and an operator's IP services 322. The EPS can interconnect with other access networks, but its entities / interfaces are not shown for simplicity. As shown, the EPS provides packet-switched services, but as one of ordinary skill in the art will readily appreciate, the various concepts presented throughout this disclosure may be extended to networks that provide circuit-switched services.

The E-UTRAN includes an evolved Node B (eNB) 306 and other eNBs 308. The eNB 306 provides user and control plane protocol terminations to the UE 302. eNB 306 may be connected to other eNBs 308 via an X2 interface (i.e., a backhaul). eNB 306 may also be referred to by those skilled in the art as a base station, a base transceiver station, a base transceiver station, a radio transceiver, a transceiver function, a base service set (BSS), an extended services set (ESS) It is possible. The eNB 306 provides an access point to the EPC 310 for the UE 302. Examples of UEs 302 include a cellular telephone, a smart phone, a session initiation protocol (SIP) telephone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, An audio player (e.g., an MP3 player), a camera, a game console, or any other similar functional device. The UE 302 may be 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 communication device, a remote device, a mobile subscriber station, , A mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other appropriate terminology.

The eNB 306 is connected to the EPC 310 by an S1 interface. EPC 310 includes a Mobility Management Entity (MME) 312, other MMEs 314, a serving gateway 316, and a Packet Data Network (PDN) gateway 318 . The MME 312 is a control node that processes the signaling between the UE 302 and the EPC 310. In general, the MME 312 provides bearer and connection management. All user IP packets are transmitted via the serving gateway 316 to which the PDN gateway 318 itself is connected. The PDN gateway 318 provides UE IP address assignment as well as other functions. The PDN gateway 318 is connected to the IP services 322 of the operator. The operator's IP services 322 include the Internet, an intranet, an IP Multimedia Subsystem (IMS), and a PS Streaming Service (PSS).

4 is a diagram illustrating an example of an access network in an LTE network architecture. In this example, the access network 400 is divided into a plurality of cellular areas (cells) 402. ENBs 408 and 412 of one or more lower power ratings may each have cellular areas 410 and 414 overlapping one or more of the cells 402. The lower power class eNBs 408 and 412 may be femtocells (e. G., Home eNBs (HeNBs)), picocells, or microcells. A higher power class or macro eNB 404 is assigned to the cell 402 and is configured to provide an access point to the EPC 310 for all UEs 406 in the cell 402. [ In this example of the access network 400, there is no centralized controller, but a centralized controller may be used in alternative configurations. The eNB 404 is responsible for all wireless related functions including radio bearer control, admission control, mobility control, scheduling, security, and connectivity to the serving gateway 316 (see FIG. 3).

The modulation and multiple access schemes employed by the access network 400 may vary according to the particular communication standard being developed. In LTE applications, OFDM is used on DL and SC-FDMA is used on UL to support both frequency division duplexing (FDD) and time division duplexing (TDD). As the skilled artisan will readily appreciate from the detailed description that follows, the various concepts presented herein are well suited for LTE applications. However, these concepts may be easily extended to other communication standards employing different modulation and multiple access techniques. For example, these concepts may be extended to EV-DO (Evolution-Data Optimized) 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 employ CDMA to provide broadband Internet access to mobile stations. These concepts include Universal Terrestrial Radio Access (UTRA) employing Wideband-CDMA (W-CDMA) and other variants of CDMA such as TD-SCDMA; A Global System for Mobile Communications (GSM) employing TDMA; And Evolved UTRA (U-UTRA), UMB, IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDM employing OFDMA. UTRA, E-UTRA, UMTS, LTE and GSM are described in documents from the 3GPP framework. CDMA2000 and UMB are described in documents from 3GPP2 mechanism. The actual wireless communication standard and multiple access techniques employed will depend on the overall design constraints imposed on the system and the particular application.

The eNB 404 may have multiple antennas supporting MIMO technology. The use of the MIMO technique enables the eNB 404 to use the spatial domain to support spatial multiplexing, beamforming, and transmit diversity.

Spatial multiplexing may be used to simultaneously transmit different streams of data on the same frequency. The data streams may be transmitted to a single UE 406 to increase the data rate, or to multiple UEs 406 to increase the overall system capacity. This is accomplished by precoding each data stream and then transmitting each spatially precoded stream over a different transmit antenna on the downlink. Spatially precoded data streams arrive at UE (s) 406 with different spatial signatures, and the signatures are transmitted to each of the UE (s) 406 with one or more data streams scheduled for that UE 406 . On the uplink, each UE 406 transmits a spatially precoded data stream that enables the eNB 404 to identify the source of each spatially precoded data stream.

Spatial multiplexing is commonly used when channel conditions are good. When the channel conditions are less favorable, beamforming may be used to focus the transmit energy in more than one direction. This may be accomplished by spatially precoding the data for transmission over 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.

Various frame structures may be used to support DL and UL transmissions. An example of the DL frame structure will now be presented with reference to FIG. However, as those skilled in the art will readily appreciate, the frame structure for any particular application may vary depending on any number of factors. In this example, the frame (10 ms) is divided into ten equal-sized sub-frames. Each sub-frame contains two consecutive time slots.

A resource grid may be used to represent two time slots each containing a resource block. The resource grid is divided into a number of resource elements. In LTE, the resource block includes 12 consecutive subcarriers in the frequency domain and 7 consecutive OFDM symbols in the time domain for a normal cyclic prefix in each OFDM symbol, or 84 resources Elements. As indicated by R 502,504, some of the resource elements include DL reference signals (DL-RS). The DL-RS includes a cell-specific RS (CRS; also sometimes referred to as a common RS) 502 and a UE-specific RS (UE-RS) The UE-RS 504 is only transmitted on resource blocks to which the corresponding physical downlink shared channel (PDSCH) is mapped. The number of bits carried by each resource element depends on the modulation scheme. Thus, the more resource blocks the UE receives and the higher the modulation scheme, the higher the data rate for the UE.

An example of the UL frame structure 600 will now be presented with reference to FIG. Figure 6 shows an exemplary format for UL in LTE. The available resource blocks for the UL may be divided into a data section and a control section. The control section may be formed at two edges of the system bandwidth and may have a configurable size. The resource blocks in the control section may be assigned to the UEs for transmission of control information. The data section may include all resource blocks not included in the control section. The design of Figure 6 results in a data section containing adjacent subcarriers, which may cause a single UE to be allocated all adjacent subcarriers in the data section.

In order to transmit control information to the eNB, resource blocks 610a, 610b in the control section may be assigned to the UE. Also, in order to transmit data to the eNB, the resource blocks 620a, 620b in the data section may also be allocated to the UE. The UE may transmit control information in the physical uplink control channel (PUCCH) on the allocated resource blocks in the control section. The UE may transmit only data information in the physical uplink shared channel (PUSCH) on the allocated resource blocks in the data section or both data and control information. The UL transmission may be over two slots in the subframe, as shown in FIG. 6, or may hop across the frequency.

As shown in FIG. 6, a set of resource blocks may be used to perform initial system access and achieve UL synchronization in a physical random access channel (PRACH) 630. PRACH 630 carries a random sequence and can not carry any UL signaling. Each random access preamble occupies a bandwidth corresponding to six consecutive resource blocks. The start frequency is specified by the network. That is, transmission of the random access preamble is limited to specific time and frequency resources. For PRACH, there is no frequency hopping. The PRACH attempt is carried in a single sub-frame (1 ms), and the UE can only make a single PRACH attempt per frame (10 ms).

PUCCH, PUSCH, and PRACH in LTE are described in 3GPP TS 36.211 entitled " Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation ".

The wireless protocol architecture may take various forms depending on the particular application. An example of an LTE system will now be presented with respect to FIG. 7 is a conceptual diagram illustrating an example of a wireless protocol architecture for user and control planes.

7, the wireless protocol architecture for the UE and the eNB includes three layers; Layer 1, Layer 2, and Layer 3. Layer 1 is the lowest layer and implements various physical layer signal processing functions. Layer 1 will be referred to herein as the physical layer 706. Layer 2 (L2 layer 708) is above the physical layer 706 and is responsible for linking between the UE and the eNB on the physical layer 706.

In the user plane, the L2 layer includes a media access control (MAC) sublayer 710, a radio link control (RLC) sublayer 712, and a packet data convergence protocol (PDCP) 714, which terminate at the eNB on the network side. Although not shown, the UE may terminate in a network layer (e.g., IP layer) terminating in a PDN gateway 308 (see FIG. 3) on the network side and in another connection (e.g., Lt; RTI ID = 0.0 > layer < / RTI >

The PDCP layer 714 provides multiplexing between the different radio bearers and the logical channels. The PDCP sublayer 714 also provides header compression for upper layer data packets to reduce radio transmission overhead, security by encryption of data packets, and handover support for UEs between eNBs. The RLC sublayer 712 includes a data packet 710 for compensating for out-of-order reception due to segmentation and reassembly of upper layer data packets, retransmission of lost data packets, and hybrid automatic repeat request (HARQ) Lt; / RTI > The MAC sublayer 710 provides multiplexing between the logical and transport channels. The MAC sublayer 710 is also responsible for allocating various radio resources (e.g., resource blocks) within a cell between UEs. The MAC sublayer 710 is also responsible for HARQ operations.

In the control plane, the radio protocol architecture for the UE and the eNB is substantially the same as for the physical layer 706 and L2 layer 708, except that there is no header compression for the control plane. The control plane also includes a radio resource control (RRC) sublayer 716 within layer 3. The RRC sublayer 716 is responsible for obtaining radio resources (i.e., radio bearers) and configuring the lower layers using RRC signaling between the eNB and the UE. 8 is a block diagram of an eNB 810 in communication with a UE 850 in an access network. At the DL, higher layer packets from the core network are provided to the controller / processor 875. Controller / processor 875 implements the L2 layer functionality described earlier in connection with FIG. In the DL, a controller / processor 875 provides radio resource assignments for UE 850 based on header compression, encryption, packet segmentation and reordering, multiplexing between logical and transport channels, and various priority metrics . The controller / processor 875 is also responsible for HARQ operations, retransmission of lost packets, and signaling to the UE 850.

TX process 816 implements various signal processing functions for the L1 layer (i.e., the physical layer). The signal processing functions may include forward error correction (FEC) at UE 850 and various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK) Shift keying (M-PSK), and M-quadrature amplitude modulation (M-QAM)) to the signal constellation diagrams. Next, the coded and modulated symbols are divided into parallel streams. Each stream is then mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and / or frequency domain, and then a physical channel is generated carrying the time domain OFDM symbol stream Lt; / RTI > are synthesized together using a fast Fourier transform (IFFT). The OFDM stream is spatially precoded to produce a plurality of spatial streams. The channel estimates from channel estimator 874 may be used to determine coding and modulation schemes as well as for spatial processing. The channel estimate may be derived from the reference signal and / or channel state feedback transmitted by the UE 850. [ Next, each spatial stream is provided to a different antenna 820 via a separate transmitter 818TX. Each transmitter 818TX modulates the RF carrier into a respective spatial stream for transmission.

In the UE 850, each receiver 854RX receives a signal via its respective antenna 852. [ Each receiver 854RX recovers the modulated information on the RF carrier and provides the information to a receiver (RX) processor 856. [

RX processor 856 implements various signal processing functions of the L1 layer. RX processor 856 performs spatial processing on the information to recover any spatial streams destined for UE 850. [ If multiple spatial streams are scheduled for UE 850, then these multiple spatial streams may be combined into a single OFDM symbol stream by RX processor 856. Next, the RX processor 856 transforms the OFDM symbol stream from the time domain to the frequency domain using Fast Fourier Transform (FFT). The frequency domain signal has a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier and the reference signal are recovered and demodulated by determining the most likely signal constellation points transmitted by eNB 810. [ These soft decisions may be based on channel estimates computed by channel estimator 858. [ Next, soft decisions are decoded and deinterleaved to recover the data and control signals originally transmitted by the eNB 810 on the physical channel. Next, the data and control signals are provided to the controller / processor 859.

Controller / processor 859 implements the L2 layer described earlier in connection with FIG. At UL, controller / processor 859 provides control signal processing for demultiplexing between transmission and logical channels, packet reassembly, decoding, header decompression, and restoration of upper layer packets from the core network. Next, the upper layer packets are provided to a data sink 862 representing all the protocol layers on the L2 layer. Various control signals may also be provided to the data sink 862 for L3 processing. Controller / processor 859 is also responsible for error detection using acknowledgment (ACK) and / or negative acknowledgment (NACK) protocols to support HARQ operations.

In the UL, a data source 867 is used to provide upper layer packets to the controller / processor 859. The data source 867 represents all protocol layers on the L2 layer (L2). Similar to the functionality described with respect to DL transmissions by the eNB 810, the controller / processor 859 may be configured to perform logical compression based on header compression, encryption, packet segmentation and reordering, and radio resource assignments by the eNB 810, And an L2 layer for the user plane and the control plane by providing multiplexing between transport channels. Controller / processor 859 is also responsible for HARQ operations, retransmission of lost packets, and signaling to eNB 810.

The channel estimates derived by the channel estimator 858 from the reference signal or feedback sent by the eNB 810 may be used by the TX processor 868 to select appropriate coding and modulation schemes and facilitate spatial processing, have. The spatial streams generated by TX processor 868 are provided to different antennas 852 via separate transmitters 854TX. Each transmitter 854 TX modulates the RF carrier into a respective spatial stream for transmission.

The UL transmission is processed in the eNB 810 in a manner similar to that described in connection with the receiver function at the UE 850. Each receiver 818RX receives a signal via its respective antenna 820. Each receiver 818RX reconstructs the modulated information on the RF carrier and provides the information to RX processor 870. [ The RX processor 870 implements the L1 layer.

Controller / processor 859 implements the L2 layer described earlier in connection with FIG. In the UL, controller / processor 859 provides control signal processing for demultiplexing, packet reassembly, decoding, header decompression, and restoration of higher layer packets from UE 850 between transmission and logical channels. The higher layer packets from the controller / processor 875 may be provided to the core network. Controller / processor 859 is also in charge of error detection using ACK and / or NACK protocols to support HARQ operations.

The processing system 104 described in connection with FIG. 1 may include an eNB 810. In particular, the processing system 104 may include a TX processor 816, an RX processor 870, and a controller 875.

Certain embodiments of the present invention provide methods and apparatus for enabling and disabling uplink and downlink SPS for LTE VoIP services. Certain embodiments incorporate eNB robust header compression (ROHC) functionality with the eNB MAC scheduler using the ROHC interface module (RIM). UE ROHC functionality is typically not affected. The uplink SPS operation may be activated when the ROHC compressor in the eNB operating in the first order (FO) state enters the second order (SO) state. The downlink SPS operation may be activated during a "talk period" in accordance with the eNB compressor. The eNB ROHC decompressor and compressor may be operated to employ selected conditions to produce a maximum header compression that results in a minimum packet size as they are possible. Otherwise, both downlink and uplink SPS functionality may be deactivated. This approach does not substantially affect ROHC functionality. The uplink and downlink SPS may also be activated during a "silence period" 904 depending on the state of the eNB ROHC decompressor and compressor. In some embodiments, activation during the silence period may not be as efficient as other activation methods disclosed herein.

An LTE system including the example described herein is a packet-switching system. As a result, the voice service using the LTE network can also provide packet-switched services such as Internet Protocol (IP) -based services, in contrast to circuit-switched services such as Global System for Mobile Communications (GSM) or Universal Mobile Telephone System . The voice service may be provided in an LTE network using voice over IP (VoIP) with an IP Multimedia System (IMS) or other voice service, such as Skype. VoIP services in LTE networks may require the use of ROHC and SPS to provide high quality of service (QoS) to high capacity voice services.

In certain embodiments, the ROHC compresses the size of the RTP / UDP / IP header (IPv4 or IPv6) down to a minimum of 3 bytes. This may be particularly important when the service is used by a large number of LTE VoIP users and when the capacity is limited by a large number of available control channels. The SPS may eliminate the need for physical downlink control channel (PDCCH) resources for each uplink and downlink resource granting, and thus, when many users desire VoIP services, each downlink and uplink The overhead required to support link resource approvals may be a limiting factor, thus providing significant advantages. The SPS allows the eNB to allocate UE resources for a period of time. These resources may be allocated on the control channel.

In certain embodiments, when the eNB ROHC modules make a determination to request activation or deactivation of either the uplink or the downlink to the LTE VoIP radio bearer, the request may be made using the ROHC interface module (RIM) eNB MAC scheduler. In response, the eNB MAC scheduler may activate or deactivate the SPS.

The adaptive multi-rate (AMR) speech codec may be based on an algebraic code excited linear prediction (ACELP) algorithm and may include a multi-rate speech codec and a voice activity generator (VAD) A source control rate (SCR) scheme, a comfort noise generation system, and an error concealment mechanism to prevent effects of transmission errors and lost frames. Figure 9 illustrates certain characteristics of a voice service using an AMR speech codec wherein the AMR speech codec includes a speech frame 908 every 20 milliseconds during a "talk period" 902, SID ") frame 910 every 160 milliseconds during a period of time (e.g., 904).

For real-time applications such as VoIP, the overhead due to RTP, UDP and IP headers is 40 bytes in IPv4 and 60 bytes in IPv6. The size of the bandwidth efficient AMR speech codec payload for 12.2 kbps is 32 bytes, while for SID 910 it is 7 bytes. The 12.2 kbps AMR speech codec payload corresponds roughly to 125% header overhead for IPv4 and 187% for IPv6. This SID 910 payload corresponds approximately to 571% header overhead for IPv4 and 857% header overhead for IPv6. This large overhead is excessive for LTE VoIP and can cause severe degradation in spectral efficiency. Thus, certain embodiments employ header compression.

ROHC describes a set of header compression mechanisms for compressing IP-based protocol headers. The ROHC framework specifies common features of the compressor and decompressor, such as mode, state, and packet type. Specific conditions may include a compressor state, a decompressed state, a mode, and a packet type.

In the compressor state, an initialization and refresh (IR) state, a primary (FO) state, and a secondary (SO) state are designated.

In the decompressed state, a No Context (NC) state, a Static Context (SC) state, and a Full Context (FC) state are designated.

In the mode state, a unidirectional mode (U-mode), a bidirectional optimistic mode (O-mode), and a bidirectional reliable mode (R-mode) are designated. In the O-mode and IR-mode, the decompressor transmits NACKs when the decompressor is unable to decompress the packet. In R-mode, when the decompressor successfully decompresses the packet, the decompressor sends ACKs.

The compressor packet type may be handled by sending different types of packets to the outside depending on the state of the compressor. In the IR-mode, the compressor transmits the IR packet, which contains the fields of the headers in an uncompressed format and can be decompressed independently. In response, the decompressor may send a feedback packet, which may include both a request to transition from the U-mode to the O-mode and an acknowledgment (ACK), in another mode, for example. This conversion may depend on the state of the decompressor. In the FO state, an IR-DYN packet containing only the dynamic portion of the context is transmitted. In the SO state, packets with fully compressed headers are transmitted.

10 illustrates an example of O-mode operation applied to LTE VoIP on the uplink during the AMR speech codec "talk period" 902. Downlink acquisition may be performed in a similar manner (with the exception that the particular directions (indicated by the arrows) may be inverted and the compressor may be implemented in the eNB, while the decompressor may be implemented in a user equipment Lt; / RTI > In Figure 10, the AMR speech codec is configured for bandwidth efficient operation at 12.2 kbps by an RTP payload comprising a single speech frame 908. For clarity and simplicity, PDCCH uplink and downlink acknowledgments and SPS activation and deactivation are not shown. Also, the uplink and downlink PUCCH, PHICH HARQ ACKs, and NACKs are not shown. Figure 10 does not account for the overhead due to PDCP, RLC, and MAC layers.

In Fig. 10, the stage 1 compressor mode is initialized to U-mode and IR state. The decompression mode is initialized to U-mode and NC state. The IR state of the compressor is used to initialize the decompressor in the static and dynamic contexts. To achieve this, in step 2, the compressor sends the IR packet to the decompressor. Once the IR packet is successfully received, the decompressor sends an ACK and then switches to the SC state.

The compressor may remain in the U-mode and IR states until it receives feedback from the decompressor. This feedback is an ACK indicating that the IR packet was decompressed correctly. The feedback also includes a request for the compressor to switch from step 3 to Q-mode.

In step 3, the compressor switches to the O-mode and the FO state and begins to send initialization and refresh dynamic (IR-DYN) packets to the decompressor. This is typically accomplished in step 4. As can be seen in steps 5 and 8 of Figure 10, the decompressor communicates only changes to the dynamic portion of the contexts. ROHC feedback is transmitted in step 6, and a new VoIP packet is transmitted in step 7. The decompressor may acknowledge receipt of two IR-DYN packets and then switch to the FC state. The compressor remains in the FO state until it is convinced that the decompressor knows the dynamic context. When the compressor enters the SO state, the compressor may begin to compress the UO-0 packets. The UO-0 packets may include fully compressed headers (as illustrated in steps 9 through 14). At this point, the eNB may activate the SPS to avoid control channel restrictions.

In step 15 of Figure 10, the decompressor fails to successfully decode the UO-0 packet that was sent by the compressor. In step 16, a new VoIP packet is transmitted. In step 17, the decompressor successfully decodes the next UO-0 packet after it has been transmitted by the compressor. This causes the decompressor to lose both the static and dynamic contexts and enter the NC state. Once in the NC state, the decompressor sends a STATIC-NACK to the compressor, as can be seen in steps 18 and 19. At this point in time, the eNB deactivates the SPS. After receiving the STATIC-NACK from the decompressor, the compressor switches to the IR state and sends the IR packet to the decompressor in step 20. At this point, the entire call flow is repeated until the compressor once again enters the SO state.

Dynamic scheduling may be specified as the default uplink and downlink scheduling mechanism for LTE. With dynamic scheduling, the eNB scheduler can have maximum flexibility for scheduling uplink and downlink HARQ transmissions and retransmissions for multiple UEs using link adaptation. To optimize link adaptation, the eNB measures (1) the UE SRS for use in uplink scheduling algorithms, and (2) receives and processes CQI reports from the UE for use in downlink scheduling algorithms.

A disadvantage of using dynamic scheduling is ensuring that PDCCH resources are consumed for each uplink and downlink resource grant and as a result all UEs may be scheduled appropriately according to their specific quality of service (QoS) requirements. , Some form of PDCCH resource management is required in the eNB scheduler.

In LTE, speech frames 908 typically have a constant periodicity during the "talk period" 902, and also have a small fixed packet size. When there are a large number of LTE VoIP users, the number of PDCCH resources required for dynamic scheduling can raise problems. SPS is the mechanism used to address this problem.

For the LTE VoIP service, the SPS requires allocation of a fixed set of repeated resource blocks for initial HARQ transmission of each speech frame 908 during the "talk period ". Dynamic scheduling may be used for HARQ retransmissions of speech frames 908. [ During "silence period" 904, dynamic scheduling may be used for both initial HARQ transmission and retransmissions of SID frames 910. [

In both uplink and downlink SPS activation, only the initial HARQ transmission of the first speech frame 908 during the "talk period" 902 requires a PDCCH resource to allocate a fixed set of repeated resource blocks (One PDCCH resource is required for uplink resource acknowledgment and one PDCCH resource is required for downlink resource acknowledgment for each downlink HARQ process configured for downlink SPS).

SPS deactivation of both uplink and downlink may require one PDCCH resource for uplink deactivation and one PDCCH resource for downlink deactivation SPS may be required for downlink SPS deactivation.

The periodicity may be configured using higher layer signaling, such as a radio resource control (RRC) protocol.

In embodiments of the present invention, once the eNB ROHC decompressor has entered the FC state and the eNB ROHC compressor has entered the SO state, or, in other words, when maximum header compression has been achieved and resulted in a minimum possible packet size, &Quot; and " downlink " are activated during the "talk period"

11 and 12 illustrate the process flow of an embodiment of an uplink SPS activation algorithm for LTE VoIP. The decompressor in the eNB is initialized to U-mode and NC state. The uplink SPS state is initialized to "inactive ".

The decompressor listens for sockets for an LTE VoIP radio bearer RLC-UM service access point (SAP). If the decompressor receives an IR packet during a listening phase that includes either the AMR speech frame 908 or the SID frame 910, the decompressor may switch to O-mode if the IR packet is successfully decoded Lt; RTI ID = 0.0 > FEEDBACK-2 < / RTI > This may cause the decompressor to switch to pending O-mode and SC states. However, if the IR packet is not successfully decoded, the compressor may send a FEEDBACK-2 packet containing a STATIC-NACK and remain in the U-mode and NC states.

When the decompressor enters the pending O-mode and the SC state, the decompressor adds the " N "incoming IR-DYN packets containing either the AMR speech frame 908 or the SID frame 910 Normally listen for a socket. When the decompressor successfully decodes "N" IR-DYN packets and is confident that it knows the dynamic context, the decompressor generates an "N" "N" FEEDBACK-2 packets containing ACKs for the successfully decoded IR-DYN packets, and switches to O-mode and FC state.

At this point, the decompressor is configured to receive UO-1 packets including AMR speech frames 908, or UO-1-TS packets including either AMR speech frame 908 or SID frame 910 Lt; / RTI > The decompressor may receive a UO-1-TS packet comprising an AMR speech frame 908 because if it is the first AMR speech frame 908 in the "talk period" 902, This is because the compressor typically has to transmit UO_1-TS packets. In this scenario, the AMR speech codec sets the marker bit M = 1 for the first speech frame 908 in the "talk period" 902 and the UO-1-TS packet contains the marker bits for the M field , And the UO-0 packet is not. The decompressor may receive a UO-1-TS packet comprising a SID frame 910, and the UO-1-TS packet may contain a SID frame 910 because the periodicity of the SID frames 910 is 160 milliseconds instead of 20 milliseconds While the RTP timestamp context is updated, the UO-0 packet is not.

If the decompressor fails to decode a UO-0 or UO-1-TS packet while the decompressor is in O-mode and FC state, it may simply send feedback in the form of NACK or STATIC-NACK have. Typically, ACKs are not transmitted. When ACKs are transmitted, if the uplink SPS is currently active, the decompressor may send a primitive to the MAC sublayer to deactivate the uplink SPS.

If the decompressor receives and successfully decodes a UO-0 or UO-1-TS packet that includes the AMR speech frame 908, if the uplink SPS is not currently active, The decompressor may send a primitive to the MAC sublayer. If the decompressor receives and successfully decodes the UO-1-TS packet containing the SID frame 910, if the uplink SPS is currently active, the decompressor may send a primitive MAC sublayer.

The decompressor may determine whether the UO-1-TS packet includes the AMR speech frame 908 or the SID frame 910 by checking the packet length of the received PDCP PDU. Note that since the payload length field in the IPv6 header carrying the length of the data carried after the IPv6 header is not included in either the static or the dynamic ROHC context, the packet length should usually be deduced.

11 and 12, when the decompressor is in the O-mode and FC state and receives either the UO-0 or UO-1-TS packet including the AMR speech frame 908, The AMR speech codec is in the "Talk Period" 902 and the decompressor in the eNB sends "N" FEEDBACK-2 packets containing ACKs for successfully decoded IR- If it has just completed, the uplink SPS may be in the "inactive" state. At this point, the compressor in the UE has just switched from the "silence period" 904 to the "talk period" 902 and the compressor in the UE is currently in O-mode and SO state. The AMR speech codec in the UE has just switched from the "silence period" 904 to the "talk period" 902 and the uplink SPS is in the & There may be.

In both of these scenarios, the UE needs to send a Buffer Status Report (BSR) to the eNB to receive the uplink resource grant. As a result, the first UO-0 or UO-1-TS packet comprising the AMR speech frame 908 during a "talk period" 902 may need to be dynamically scheduled, which requires a PDCCH resource.

In certain embodiments, in accordance with the eNB MAC scheduler implementation, it is possible to reserve a specific SPS logical channel group (e.g., 0) so that only the UE's LTE VoIP radio bearer is mapped to a reserved SPS logical channel group for BSR reporting It may be possible. This leaves three remaining logical channel groups to which all of the UE's remaining Signaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs) can be mapped. Upon reception of a short BSR and truncated BSR MAC control element from the UE (which is a BSR containing only one LCG ID field and one corresponding buffer size field), the smart eNB MAC scheduler determines whether the compressor is in a buffer It can be determined that it is in the SO state based on the size field. This may be done prior to dynamically scheduling the UO-0 or UO-1-TS packet based on the value of the Buffer Size field in the BSR. Next, the eNB MAC scheduler may activate the SPS using the PDCCH resource. At a later time, the eNB MAC scheduler may send the primitive to the decompressor then to notify the decompressor that the uplink SPS state is active.

A similar situation occurs during the downlink SPS operation when the ROHC decompressor in the UE in the FC state needs to send a FEEDBACK-2 packet containing a NACK or STATIC NACK. To do this, although the uplink SPS may be in an active state, the UE needs to first transmit the BSR to the eNB to receive the uplink resource grant. This should typically be done because the size of the fixed resources used during the uplink SPS operation that carries the AMR speech frame 908 can not accommodate both the AMR speech frame 908 and the FEEDBACK-2 packet.

Figures 13 and 14 illustrate the downlink SPS activation process for LTE VoIP. In the process, the compressor in the eNB is initialized to U-mode and IR state and the downlink SPS state is initialized to "deactivated ". The PDCP buffer is first polled and then the compressor sends an IR packet containing either the AMR speech frame 908 or the SID frame 910. [ If the decompressor does not successfully decode the IR packet, the decompressor may respond with a FEEDBACK-2 packet containing a STATIC-NACK, and the compressor may select either the AMR speech frame 908 or the SID frame 910 And transmits a second IR packet including one. This process may continue until the decompressor successfully decodes the IR packet and responds with a FEEDBACK-2 packet containing a request to switch to O-mode and an ACK.

Once the compressor switches to the O-mode and the FO state, the compressor may send "N" IR-DYN packets. The compressor may be maintained in the FO state until the transmitter is assured that the decompressor knows the dynamic context. In one example, after the decompressor successfully decodes both transmitted IR-DYN packets, the compressor may receive two FEEDBACK-2 packets containing ACKs. At this point in the process, the compressor may switch to the SO state.

If the next packet requesting transmission is an AMR speech frame 908, then if the downlink SPS is not currently active, the compressor may send a primitive to the MAC sublayer to activate or reactivate the downlink SPS. If this is not the first AMR speech frame 908 in the "talk period" 902, the compressor may send a UO-0 packet. If this is the first AMR speech frame 908 in the "Talk Period" 902, then the compressor would normally have to transmit the UO-1-TS packet first.

If the next packet to be transmitted is the SID frame 910, then if the downlink SPS is currently active, the compressor may send a primitive to the MAC sublayer to deactivate the downlink SPS. Because the periodicity of the SID frames 910 is 160 milliseconds instead of 20 milliseconds, the compressor may then transmit a UO-1-TS packet that updates the RTP time stamp context.

The compressor may determine whether the packet in the PDCP buffer is an AMR speech frame 908 or a SID frame 910 by checking the payload length field in the IPv6 header. This field carries the length of the data carried after the IPv6 header.

When the compressor is in O-mode and SO state, the decompressor sends feedback only in the form of NACK or STATIC NACK. ACK messages are not normally transmitted. When the compressor receives a FEEDBACK-2 packet containing either NACK or STATIC NACK, the compressor transmits the primitive to the MAC sublayer to deactivate the downlink SPS if the downlink SPS is currently active.

FIG. 15 illustrates a simplified eNB user plane architecture that emphasizes ROHC interface module (RIM) 1502. RIM 1502 may be utilized to implement both uplink and downlink SPS activation and deactivation.

One LTE VoIP radio bearer is illustrated in FIG. RTCP may be turned off by granting 0 kbps bandwidth during session establishment or modification via SIP and SDP. As a result, LTE VoIP supports only one traffic flow that includes one payload type and only one ROHC context (e. G., CID = 0) in the eNB ROHC module. The radio bearer represents the wireless-interface portion of the overall dedicated EPS bearer. In Fig. 15, the dedicated EPS bearer has QCI = 1, which is conversational class Quality of Service (QoS).

The RIM 1502 interfaces with the MAC scheduler 1504 using three request primitives and three response primitives as shown in Table 1. These interfaces may be used to enable and disable both uplink and downlink SPS operations.

Table 2 illustrates the RIM interfaces with the eNB MAC scheduler using three request primitives and three response primitives to activate, modify, and deactivate the downlink SPS.

The request primitives that modify the uplink and downlink SPS are needed when the SPS can be activated during the "silence period" 904 as well as during the "talk period ", which may result from 328 bits (and 2 PRBs) Will require a change in the MAC TBS to 120 bits (and 1 PRB). When the eNB decompressor (in either the U or O-mode) is in the NC or SC state and the compressor (also operating in either the U or O-mode) is in the IR or FO state, Request primitives may also be used when the operator wishes to activate the uplink and downlink SPS during "talk period" 902. This state occurs before maximum header compression is achieved and requires a change in MAC TBS from 328 bits (and 2 PRBs) to 776 bits (and 5 PRBs).

Table 3 shows the eNB MAC scheduler, and its interfaces with the RIM. These interfaces are in the form of two indication primitives used to update the status of the uplink and downlink SPS.

Table 4 shows how the RIM informs the eNB RLC-UM that the downlink SPS is not segmented or connected (currently identified by the PDCP PDU size) RTI ID = 0.0 > RLC-UM < / RTI > In order to provide flexibility to handle the case where the size of the PDCP PDU of the RTCP packet is the same as the size of the PDCP PDU of the RTP packet, the eNB RLC-UM entity determines whether the PDCP PDU can be segmented or connected and for dynamic scheduling or SPS It may be necessary to employ heuristics that allow a determination as to whether to transmit the resulting RLC-UM PDU to the eNB MAC scheduler.

Certain embodiments provide SPS activation during the silence period. Currently, according to 3GPP specifications, either the uplink or the downlink SPS may be activated when the eNB ROHC decompressor is in the FC state and the compressor is in the SO state; This approach is the next best thing. This occurs because the periodicity of the SID frames 910 is 160 milliseconds and the AMR speech frames 908 is 20 milliseconds. The size of the SPS resource allocation can be changed using the "SPS" PDCCH signaling, but the SPS periodicity can not be changed. Changing the SPS periodicity requires the execution of an RRC connection reconfiguration procedure using RRC signaling, which is not desired and, if possible, generally avoided.

Some embodiments provide that the RRC protocol may be changed to configure the uplink and downlink periodicity for the UE. semiPersistSchedIntervalUL may be set to 20 milliseconds, and semiPersistSchedIntervalDL is also set to 20 milliseconds. The embodiment requires the addition of two new parameters: semiPersistSchedIntervalUL-SID set to 160 milliseconds and semiPersistSchedIntervalDL-SID set to 160 milliseconds.

Additionally, a one-bit field called "P " may be added to the" SPS "PDCCH activating both the uplink and downlink SPS. If P = 0, the periodicity is determined by the parameters semiPersistSchedIntervalUL for uplink SPS activation and semiPersistScheduIntervalDL for downlink SPS activation. If P = 1, the periodicity is determined by the parameters semiPersistSchedIntervalUL-SPS for uplink SPS activation and semiPersistSchedInterval-DL-SPS for downlink SPS activation.

Some embodiments provide for enabling and disabling the SPS in the eNB ROHC module in the context of a multi-party or conference call. A multi-party call may be initiated when UE 1 and UE 2 participate in a two-way call. If the call is originating on an LTE network, the RTCP for both parties is turned on. In an LTE network, the RTCP may be turned off for speech-only sessions. As a result, the LTE VoIP-only EPS bearer for each UE typically supports only one traffic flow, RTP, including one payload type, as shown in FIG.

UE 1 may decide that a conference call should be initiated. Before an additional party can be added, UE 1 puts UE 2 in a standby state. At this point, in an LTE system, RTCP must be turned on to provide link "aliveness" information.

The next step in the multi-party call requires that UE 1 initiate a session for UE 3 and obtain permission from UE 3 to join the multi-party call. At this point, the LTE VoIP-only EPS bearer for UE 1 typically has to support two traffic flows, RTCP flow to and from UE 2, and RTP flows to and from UE 3, Each traffic flow includes one payload type, as illustrated in FIGS. 16 and 17. FIG. Assuming that a ROHC profile for UDP / IP header compression is used for RTCP, there are now three ROHC contexts, CID = 0, 1, and 2 in the eNB ROCH module and UE 1602 ROHC module.

UE 1602 then establishes a conference or conference call using MRFC and MRFP 1608 and moves the original sessions with UE 1604 and UE 1606 to MRFC and MRFP 1608. [ At this point, since the media streams are mixed through MRFP, the LTE VoIP-only EPS bearers for UE 1602, UE 1604, and UE 1606 are again forwarded to only one traffic flow, Lt; RTI ID = 0.0 > RTP < / RTI >

In operation, the method of activating and deactivating the SPS in the eNB ROHC module may handle multiple traffic flow scenarios as described below.

If the uplink SPS is currently active, that is, if the eNB ROHC decompressor was in the FC state for CID = 0 and the AMR speech frames 908 were being received before waiting for a multiparty call , the uplink SPS may be deactivated because the eNB ROHC decompressor is in the NC state for CID = 2.

If the downlink SPS is currently active, i.e., if the eNB ROHC compressor was in the SO state for CID = 0 and the AMR speech frames 908 were being transmitted before being placed in a standby state to establish a multiparty call, Since the ROHC decompressor is in the IR state for CID = 2, the downlink SPS may be deactivated.

Some embodiments provide SPS with dual tone multi-frequency (DTMF) operation. For UEs operating in an LTE network, the UE and IMS may be required to support DTMF operation. A speech-only session, i.e., a session with RTCP turned off, may be configured with DTMF events during session establishment or modification using SIP and SDP. Typically, only the UE transmits DTMF events, but due to the nature of the SDP provisioning and response model, contrivances must be made for the UE to receive DTMF events.

18 illustrates simultaneous support of speech-only sessions and DTMF events. This concurrent support requires that an LTE VoIP-only EPS bearer may need to support one traffic flow that includes two payload types and one ROHC context (e. G., CID = 0) in the eNB ROHC module do.

The SPS activation and deactivation algorithm in the eNB ROHC module handles DTMF event scenarios in one embodiment. Embodiments are handled in the same way as uplink RTP packets including payload type "AMR speech codec" with uplink RTP packets containing specific payload type "DTMF events & 910). In this situation, the uplink SPS is deactivated.

Downlink RTP packets including payload type "DTMF events" may be processed in the same manner as downlink RTP packets including payload type "AMR speech codec" where payload SID frame 910 . In this situation, the downlink SPS is deactivated.

The DTMF functionality may also handle situations where the PDCP PDU size of the RTP packet including the AMR speech frame 908 or SID frame 910 is the same size as the PDCP PDU of the RTP packet containing the DTMF event. The methodology used may be the same as for the ROHC interface module discussed above.

Certain embodiments provide methods and apparatus for wireless communications. In some embodiments, the method includes determining an operating state of the header compressor or the header decompressor. Determining the operating state of the header compressor or the header decompressor may include determining a transition between different operating states associated with the header compressor. Determining the operating state of the header compressor or the header decompressor may include determining a transition between different operating states associated with the header decompressor.

In some embodiments, the method includes changing the persistent scheduling mode in response to a change in the operating state of the header compressor. Changing the persistent scheduling mode may include activating uplink persistent scheduling when the operating state of the header compressor changes from a primary state to a secondary state. Changing the persistent scheduling mode may include disabling uplink persistent scheduling when the operating state of the header compressor exits from the primary state. Changing the persistent scheduling mode may include activating downlink persistent scheduling when the operational state of the decompressor of the header changes from the static context state to the full context state. Changing the persistent scheduling mode may include deactivating the downlink persistent scheduling mode when the operating state of the header decompressor enters the no-context state.

In some embodiments, the persistent scheduling mode is changed during a talk period, and the talk period corresponds to the occurrence of a speech frame by the codec. In some embodiments, the persistent scheduling mode is changed when a silence descriptor is generated by the codec. In some embodiments, changing the persistent scheduling mode includes activating the persistent scheduling mode. Activating the persistent scheduling mode may include determining a fixed set of repeated resource blocks and determining the periodicity of the persistent scheduling mode.

In some embodiments, changing the persistent scheduling mode may include disabling the persistent scheduling mode. Disabling the persistent scheduling mode may include deallocating a fixed set of repeated resource blocks when the packet size is larger or smaller than the fixed set of repeated resource blocks and the periodicity of the allocation changes.

In some embodiments, a fixed set of recurring resource blocks may be modified when the packet size is greater or smaller than a fixed set of recurring resource blocks and the periodicity of the allocation changes. In some embodiments, only the uplink resource blocks are deallocated or only the downlink resource blocks are deallocated.

In certain embodiments, data generated by codecs or dual tone multi-function events is communicated using a fixed set of repeated resource blocks. Semi-persistent scheduling may be deactivated after the conference call is established. By disabling uplink semi-persistent scheduling when speech frames are being received before the conference call is established, semi-persistent scheduling may be deactivated after the conference call is established. By disabling semi-persistent scheduling after a conference call has been established, the possibility that semi-persistent scheduling may be deactivated after the conference call has been activated means that the downlink semi-persistent scheduling when speech frames were being sent before the conference call was established / RTI >

It is to be understood that the specific order or hierarchy of steps in the disclosed processes is exemplary of exemplary approaches. It should be appreciated that, based on design preferences, the specific order or hierarchy within the processes may be rearranged. The appended method claims are not intended to suggest the elements of the various steps in a sample order and to be limited to the specific order or hierarchy presented.

The previous description is provided to enable any person of ordinary skill 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. Accordingly, the claims are not intended to be limited to the embodiments shown herein but are to be accorded the full scope consistent with the written claims, and references to singular elements, unless specifically so stated, Quot ;, but rather is intended to mean "one or more. &Quot; Unless specifically stated otherwise, the term "part" refers to one or more. All structural and functional equivalents of the elements of the various aspects described throughout this disclosure, which are known or later known to those skilled in the art, are expressly incorporated herein by reference and are intended to be encompassed by the claims . Further, nothing disclosed herein is intended to be dedicated to the public whether or not such disclosure is expressly set forth in the claims. No element of claim should be construed as a means plus function unless the element is explicitly stated using the phrase "means to ".

Claims (72)

A method for wireless communications,
Determining, by the network device, the operating mode and operating state of the robust header compression (ROHC) compressor or the ROHC decompressor; and
Changing, by the network device, a semi-persistent scheduling (SPS) mode of the radio bearer in response to a change in the operational state of the ROHC compressor or the ROHC decompressor,
Wherein determining the operating mode and operating condition comprises determining a switch between different operating conditions associated with the ROHC compressor,
Wherein changing the SPS mode comprises activating uplink semi-permanent scheduling when the operating state of the ROHC compressor changes from a primary state to a secondary state and wherein the operating state of the ROHC compressor is equal to or greater than the second And deactivating the uplink semi-permanent scheduling when leaving the car state. delete delete delete The method according to claim 1,
Wherein determining the operating mode and operating state of the ROHC compressor or the ROHC decompressor includes determining a switch between different operating states associated with the ROHC decompressor by the network device. Method for communications. 6. The method of claim 5,
The step of changing the SPS mode comprises: when the operating state of the ROHC decompressor is changed from a static context (SC) state to a full context (FC) state by the network device, downlink semi-permanent scheduling The method comprising the steps of: The method according to claim 6,
Wherein changing the SPS mode comprises deactivating the downlink semi-permanent scheduling when the operating state of the ROHC decompressor is entered by the network device in a no context (NC) state , A method for wireless communications. The method according to claim 1,
Wherein the SPS mode is changed during a talk period, and wherein the talk period corresponds to the occurrence of a speech frame by a codec. The method according to claim 1,
Wherein the SPS mode is changed when a silence descriptor (SID) is generated by the codec. The method according to claim 1,
Wherein changing the SPS mode comprises activating the SPS mode,
Wherein activating the SPS mode comprises:
Determining a fixed set of repeatedly allocated resource blocks, and
And determining the periodicity of the SPS mode. 11. The method of claim 10,
The step of changing the SPS mode includes deactivating the SPS mode, wherein deactivating the SPS mode comprises: if the packet size of the transmitted frame is larger than the fixed set size of the repeatedly allocated resource blocks Or less, and when the periodicity of the allocation changes, deallocating a fixed set of the repeatedly allocated resource blocks. 12. The method of claim 11,
Modifying a fixed set of the repeatedly allocated resource blocks when the packet size of the transmitted frame is greater or smaller than the size of the fixed set of the repeatedly allocated resource blocks and the periodicity of the allocation changes The method further comprising the steps of: 12. The method of claim 11,
Only the uplink resource blocks are deallocated. 12. The method of claim 11,
And only the downlink resource blocks are deallocated. 11. The method of claim 10,
Further comprising communicating data generated by codec or dual tone multi-function (DTMF) events using a fixed set of the repeatedly allocated resource blocks. The method according to claim 1,
The step of changing the SPS mode may include applying semi-permanent scheduling between the network device and the second network device after a conference call is established between the network device, the second network device, and at least the third network device And deactivating the wireless communication. 17. The method of claim 16,
Wherein deactivating the semi-permanent scheduling after the conference call is established comprises deactivating uplink semi-permanent scheduling when speech frames are being received by the network device before the conference call is established. For example. 17. The method of claim 16,
Wherein deactivating the semi-permanent scheduling after the conference call is established comprises deactivating downlink semi-permanent scheduling when speech frames are being transmitted by the network device before the conference call is established. For example. An apparatus for wireless communication,
Means for determining an operating mode and operating state of a robust header compression (ROHC) compressor or ROHC decompressor, and
Means for changing a semi-persistent scheduling (SPS) mode of the radio bearer in response to a change in the operating state of the ROHC compressor or the ROHC decompressor,
Wherein the means for determining the operating mode and the operating condition determine a switch between different operating conditions associated with the ROHC compressor,
Wherein the means for changing the SPS mode comprises means for activating uplink semi-permanent scheduling when the operating state of the ROHC compressor changes from a primary state to a secondary state and wherein the operating state of the ROHC compressor is removed from the secondary state And upon expiration, deactivates the uplink semi-permanent scheduling. delete delete delete 20. The method of claim 19,
Wherein the means for determining the operating mode and operating state of the ROHC compressor or the ROHC decompressor determines switching between different operating states associated with the ROHC decompressor. 24. The method of claim 23,
Wherein the means for changing the SPS mode comprises means for activating downlink semi-permanent scheduling when the operating state of the ROHC decompressor changes from a static context (SC) state to a full context (FC) state, . 25. The method of claim 24,
Wherein the means for changing the semi-permanent scheduling mode deactivates the downlink semi-permanent scheduling when the operating state of the ROHC decompressor enters a no-context state. 20. The method of claim 19,
Wherein the SPS mode is changed during a talk period, and wherein the talk period corresponds to the occurrence of a speech frame by a codec. 20. The method of claim 19,
Wherein the SPS mode is changed when a silence descriptor (SID) is generated by the codec. 20. The method of claim 19,
Wherein the means for changing the SPS mode activates the SPS mode,
In the SPS mode,
Determining a fixed set of repeatedly allocated resource blocks, and
Determining the periodicity of the SPS mode
Is activated by the wireless communication device. 29. The method of claim 28,
Wherein the means for changing the SPS mode deactivates the SPS mode,
The SPS mode allocates a fixed set of the repeatedly allocated resource blocks when the packet size of the transmitted frame is larger or smaller than the fixed set size of the repeatedly allocated resource blocks and the periodicity of allocation changes And is deactivated by releasing the wireless communication. 30. The method of claim 29,
Modifying a fixed set of the repeatedly allocated resource blocks when the packet size of the transmitted frame is greater or smaller than the size of the fixed set of the repeatedly allocated resource blocks and the periodicity of the allocation changes And means for communicating with the wireless communication device. 30. The method of claim 29,
Only the uplink resource blocks are deallocated. 30. The method of claim 29,
Only downlink resource blocks are deallocated. 29. The method of claim 28,
And means for communicating data generated by codec or dual tone multi-function (DTMF) events using a fixed set of the repeatedly allocated resource blocks. 20. The method of claim 19,
Wherein the means for changing the SPS mode comprises deactivating semi-permanent scheduling between the network device and the second network device after the conference call is established between the network device, the second network device and at least the third network device. Apparatus for wireless communication. 35. The method of claim 34,
Wherein the means for deactivating the semi-permanent scheduling after the conference call is established further deactivates uplink semi-permanent scheduling when speech frames are being received by the network device before the conference call is established. 35. The method of claim 34,
Wherein the means for deactivating the semi-permanent scheduling after the conference call is established further deactivates downlink semi-permanent scheduling when speech frames are being transmitted by the network device before the conference call is established. An apparatus for wireless communication,
Processing system
/ RTI >
The processing system comprising:
Determining an operation mode and an operation state of the ROHC compressor or the ROHC decompressor,
And to change the SPS mode in response to a change in the operating state of the ROHC compressor,
Wherein determining the operating mode and operating condition comprises determining a switch between different operating conditions associated with the ROHC compressor, and
Wherein changing the SPS mode comprises activating uplink semi-permanent scheduling when the operating state of the ROHC compressor changes from a primary state to a secondary state and wherein the operating state of the ROHC compressor is in the secondary state And deactivating the uplink semi-permanent scheduling when it exits from the base station. delete delete delete 39. The method of claim 37,
Wherein determining the operating mode and operating state of the ROHC compressor or the ROHC decompressor includes determining a switch between different operating conditions associated with the ROHC decompressor. 42. The method of claim 41,
Wherein changing the SPS mode comprises activating downlink semi-permanent scheduling when the operating state of the ROHC decompressor changes from a static context (SC) state to a full context (FC) state. . 43. The method of claim 42,
Wherein changing the SPS mode comprises deactivating the downlink semi-permanent scheduling when the operational state of the ROHC decompressor enters a no-context (NC) state. 39. The method of claim 37,
Wherein the SPS mode is changed during a talk period, and wherein the talk period corresponds to the occurrence of a speech frame by a codec. 39. The method of claim 37,
Wherein the SPS mode is changed when a silence descriptor (SID) is generated by the codec. 39. The method of claim 37,
Wherein changing the SPS mode comprises activating the SPS mode,
Activating the SPS mode may include:
Determining a fixed set of repeatedly allocated resource blocks, and
And determining the periodicity of the SPS mode. 47. The method of claim 46,
Wherein changing the SPS mode comprises deactivating the SPS mode, wherein deactivating the SPS mode means that the packet size of the transmitted frame is greater or smaller than the fixed set size of the repeatedly allocated resource blocks And when the periodicity of the allocation changes, deallocating a fixed set of the repeatedly allocated resource blocks. 49. The method of claim 47,
Wherein the processing system is further configured to determine when the packet size of the transmitted frame is greater or smaller than the size of the fixed set of the repeatedly allocated resource blocks and the periodicity of the allocation changes, And to modify the set that has been transmitted. 49. The method of claim 47,
Only the uplink resource blocks are deallocated. 49. The method of claim 47,
Only downlink resource blocks are deallocated. 47. The method of claim 46,
Wherein the processing system is further configured to communicate data generated by codec or dual tone multi-function (DTMF) events using a fixed set of the repeatedly allocated resource blocks. 39. The method of claim 37,
Wherein changing the SPS mode comprises deactivating semi-permanent scheduling between the network device and the second network device after the conference call is established between the network device, the second network device, and at least the third network device. Apparatus for communication. 53. The method of claim 52,
Wherein deactivating the semi-permanent scheduling after the conference call is established comprises deactivating uplink semi-permanent scheduling when speech frames are being received by the network device before the conference call is established. Device. 53. The method of claim 52,
Wherein deactivating the semi-permanent scheduling after the conference call is established comprises deactivating downlink semi-permanent scheduling when speech frames are being transmitted by the network device before the conference call is established. Device. 22. A computer readable storage medium,
The computer readable storage medium comprising:
A code for determining an operation mode and an operation state of the ROHC compressor or the ROHC decompressor, and
And code for changing a semi-permanent scheduling (SPS) mode of the radio bearer in response to a change in the operating state of the ROHC compressor,
Wherein determining the operating mode and operating condition comprises determining a switch between different operating conditions associated with the ROHC compressor, and
Wherein changing the SPS mode comprises activating uplink semi-permanent scheduling when the operating state of the ROHC compressor changes from a primary state to a secondary state and wherein the operating state of the ROHC compressor is in the secondary state And deactivating the uplink semi-permanent scheduling when it exits. delete delete delete 56. The method of claim 55,
Wherein the code for determining the operating mode and operating state of the ROHC compressor or the ROHC decompressor determines a switch between different operating states associated with the ROHC decompressor. 60. The method of claim 59,
Wherein the code for changing the SPS mode is configured to enable downlink semi-permanent scheduling when the operating state of the ROHC decompressor changes from a static context (SC) state to a full context (FC) state, media. 64. The method of claim 60,
Wherein the code for changing the SPS mode deactivates the downlink semi-permanent scheduling when the operating state of the ROHC decompressor enters a no-context state. 56. The method of claim 55,
Wherein the SPS mode is changed during a talk period, and wherein the talk period corresponds to an occurrence of a speech frame by a codec. 56. The method of claim 55,
Wherein the SPS mode is changed when a silence descriptor (SID) is generated by the codec. 56. The method of claim 55,
The code for changing the SPS mode includes:
Determining a fixed set of repeatedly allocated resource blocks, and
Determining the periodicity of the SPS mode
To activate the SPS mode. 65. The method of claim 64,
The code for changing the SPS mode may be configured such that when the packet size of the transmitted frame is larger or smaller than the size of the fixed set of the repeatedly allocated resource blocks and the periodicity of allocation changes, And deactivating the SPS mode by de-allocating a fixed set. 66. The method of claim 65,
Wherein the computer readable storage medium further comprises a memory for storing the repeatedly allocated resource blocks when the packet size of the transmitted frame is greater or smaller than the size of the fixed set of the repeatedly allocated resource blocks and the periodicity of the allocation changes. And code for modifying a fixed set of resource blocks. 66. The method of claim 65,
Only the uplink resource blocks are deallocated. 66. The method of claim 65,
Only downlink resource blocks are deallocated. 65. The method of claim 64,
Wherein the computer readable storage medium further comprises code for communicating data generated by codec or dual tone multi-function (DTMF) events using a fixed set of the repeatedly assigned resource blocks. Possible storage medium. 56. The method of claim 55,
The computer readable storage medium further comprises code for deactivating semi-permanent scheduling between the network device and the second network device after a conference call is established between the network device, the second network device, and at least the third network device Lt; / RTI > storage medium. 71. The method of claim 70,
Wherein semi-persistent scheduling is deactivated after the conference call is established by deactivating uplink semi-permanent scheduling when speech frames are being received by the network device before the conference call is established. 71. The method of claim 70,
Wherein semiconductive scheduling is deactivated after the conference call is established by deactivating downlink semi-permanent scheduling when speech frames are being transmitted by the network device before the conference call is established.

Images