TWI538459B - Method and apparatus for supporting voice over ip services over a cellular wireless communication network - Google Patents

Description

Method and device for supporting network voice service on cellular wireless communication network

The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and system for supporting Voice over Internet Protocol (VoIP) services over a wireless communication network.

The concept of providing VoIP services over cellular wireless networks has been proposed. However, supporting VoIP services on traditional cellular wireless networks, such as the Third Generation Partnership Project (3GPP) network, is challenging. VoIP services are a variable low bit rate, delay and jitter sensitive application. Depending on the codec rate and packet header compression, the data rate for VoIP services can vary from 8 kbps to 42 kbps.

The problem with VoIP over cellular networks is the large amount of load. Voice data for VoIP can be transmitted by Instant Transfer Protocol (RTP). In addition to the link layer frame, the VoIP packet has a total of 40 octets, including the IP header (20 octets for IPv4) and the UDP header (8 octets). Bytes) and RTP headers (12 octets) group). With IPv6, the IP header is 40 octets for a total of 60 octets. The size of the payload depends on the size of the speech code and frame used, and is a byte of a certain size between 15 and 75 bytes.

In the 3GPP standard, packet switched domains, each containing control information (public and private control information). The common control information includes scheduling information, User Equipment (UE) identification, and a Transport Format Combination Indicator (TFCI) of the packet (eg, modulation and coding scheme (MCS) and packet size). The dedicated control information includes hybrid automatic repeat request (H-ARQ) processing information and transmission sequence number. The control information appends a significant load in the range of approximately 20% to the VoIP packet.

In the 3GPP standard Long Term Evolution (LTE), the physical layer null interplane is Orthogonal Frequency Division Multiplexing (OFDM) Multiple Input Multiple Output (MIMO). The uplink and downlink resources include subcarrier groups. In the uplink, the variable modulation and coding scheme can support variable data rates that are not adequately fit within the available resources. For example, if transmitted in a lower modulation and robust coding scheme, the retransmitted packet can be successfully decoded. However, in this case, it is impossible to fit the packet in the available resources.

Therefore, it is desirable to provide a method for reducing the control load associated with VoIP packets and for more flexible support of variable data rates.

The present invention relates to a method and system for supporting Voice over Internet Protocol (VoIP) services over a cellular wireless communication network. The data is encoded at a coding rate specified by the controller to generate a VoIP packet. Error-sensitive bits and perceptually insensitive-insensitive bits are identified in the encoded material, and error protection is performed separately by the Media Access Control (MAC) layer and/or the physical layer. The header of the VoIP packet is selectively compressed according to an indication from the controller. User Data Encapsulation Protocol (UDP)-Lite can be used for partial coverage of sensitive bits. UD-Lite is a variant of UDP with increased flexibility in the form of partial checksums. Comfort noise is generated by the receiving end during quiet periods without receiving a comfort noise packet from the transmitting end.

If the VoIP packet is not suitable for the currently allocated radio resource, the VoIP packet can be divided into at least two segments and sent in segments. A request for additional wireless resources may be sent with the first segment, and additional resources may be responsive to the request allocation to transmit the remaining segments using the additional wireless resource. Alternatively, the need for additional wireless resources can be implicitly known by sending segments instead of all VoIP packets. Additional resource allocations can be used for the remaining segments or all packets. The remaining segments may be transmitted using the allocated radio resources for the Hybrid Hybrid Automatic Repeat Request (H-ARQ) retransmission of the failed VoIP packet.

100‧‧‧ system

102‧‧‧Wireless Transmit/Receive Unit

110‧‧‧Wireless access network

112‧‧‧B node

114‧‧‧Wireless Network Controller

200‧‧‧ device

300, 400, 500, 600‧‧‧ methods

MAC‧‧‧Media Access Control

RLC‧‧‧Wireless Link Control

UDP‧‧‧ User Data Packet Agreement

VoIP‧‧‧ Internet Protocol Terms sound

1 is a side view of an exemplary wireless communication system configured in accordance with the present invention. Figure 2 is a block diagram of an apparatus for supporting VoIP over a wireless communication network in accordance with the present invention; Figure 3 is a flow diagram of a method for transmitting VoIP packets in the uplink, in accordance with one embodiment of the present invention. 4 is a flow chart of a method for transmitting a VoIP packet in an uplink according to another embodiment of the present invention; FIG. 5 is a diagram for transmitting VoIP in an uplink according to still another embodiment of the present invention; Flowchart of a method of packetization; Figure 6 is a flow diagram of a method for transmitting a VoIP packet in the uplink, in accordance with yet another embodiment of the present invention.

As referred to below, the term "WTRU" includes, but is not limited to, a UE, a mobile station (STA), a fixed or mobile subscriber unit, a pager, or any other type of device capable of operating in a wireless environment. As referred to below, the term "Node-B" includes, but is not limited to, a base station, a site controller, an access point (AP), or any other type of interface connection device in a wireless environment. As referred to below, the term "VoIP" includes any instant (RT) service based on IP, not limited to voice services, but any RT service, such as video services.

Features of the invention may be incorporated into an integrated circuit (IC) or may be configured in a circuit comprising a plurality of interconnected elements.

The present invention is applicable to any wireless communication system including, but not limited to, 3GPP, High Speed Packet Access (HSPA) system (HSPA+) evolution (eg, High Speed Downlink Packet Access (HSDPA) or High Speed Uplink Packet Access (HSUPA) Evolution) and LTE of the 3GPP standard.

1 is a block diagram of an exemplary wireless communication system 100 configured in accordance with the present invention. The system 100 includes a WTRU 102, a wireless access network (RAN) 110, and a core network 120. The RAN 110 includes a Node-B 112 and may also include a Radio Network Controller (RNC) 114. If the RNC 114 does not exist (e.g., in LTE), the Node-B 112 is directly connected to the core network 120. Core network 120 (which may also be referred to as an access gateway (aGW)) is connected to IP network 130. Preferably, Node-B 112 allocates radio resources to WTRU 102, and WTRU 102 transmits and receives VoIP packets over the wireless communication network 100 using the allocated resources.

2 is a block diagram of an apparatus 200 for supporting VoIP over a wireless communication network in accordance with the present invention. The apparatus 200 can be the WTRU 102 or can be an entity in the RAN 110 or core network path 120. Apparatus 200 includes a VoIP codec 202, a UDP layer 204 (preferably a UDP-Lite layer), an IP layer 206, a header compression and decompression layer 208, an RLC layer 210, a MAC layer 212, and a physical layer 214.

The VoIP codec 202 encodes the transmitted material (i.e., voice, video, or any other material) for transmission and decodes the received material. Optional adaptive multi-rate (AMR) and adaptive multi-speed Rate Broadband (AMR-WB) is used as a VoIP codec for 3GPP systems. AMR can support 8 encoding modes, and AMR-WB can support 9 encoding modes. AMR supports bit rates ranging from 4.75 kbps to 12.2 kbps, and AMR-WB supports bit rates ranging from 6.6 kbps to 23.85 kbps. The multi-rate encoding capabilities of AMR and AMR-WB are designed to maintain high quality over a wide range of transmission conditions. To perform mode adaptation, the decoder sends a Codec Mode Request (CMR) to the encoder of the communicating peer node for the preferred new mode of the decoder. The CMR can be sent together with the VoIP packet as an intra-frequency signaling.

In the AMR or AMR-WB frame, the speech or video bits encoded by the VoIP codec 202 have different perceptual sensitivities to bit errors. This feature can be used to achieve better quality by using different error protection and detection. In the encoded transmission material, the bit sensitive to the error and the bit insensitive to the error can be identified by the VoIP codec 202. The sensitive bit and the insensitive bit may be processed separately by the UDP layer 204, the MAC layer 212, or the physical layer 214 (which will be described later) for error protection.

The codec rate (i.e., encoding and decoding rate) of the VoIP codec 202 is specified by the controller 220. The controller 220 can be a standalone network entity or can be in the WTRU 102 or any other existing network entity (e.g., in the Node-B 112, RNC 114, or Radio Resource Management (RRM) entity in the core network path 120) . This guarantees a more codec rate Quickly adapt to wireless resources. Controller 220 detects changes in the wireless conditions and sends a signal to VoIP codec 202 to adjust the codec rate.

The controller 220 can transmit the CMR to the encoder (ie, the VoIP codec of the transmitting end) as an out-of-band signal. CMR represents the maximum coding rate that can be used by the encoder. Alternatively, the controller 220 may send an indication indicating that the encoding rate needs to be changed to the decoder (ie, the VoIP codec of the receiving end), and the decoder may send the CMR to the encoder of the communicating peer node in response to the indication. . Alternatively, the received CMR in the received VoIP packet received from the correspondent peer node may be modified prior to being sent to the VoIP codec 202. The VoIP data rate at the transmitting end is changed based on the transmission channel conditions. In the WTRU 102, the VoIP encoder may change the coding rate based on an out-of-frequency indication from the controller. However, on the network side, it is not possible to send an out-of-band indication. Thus, controller 220 at WTRU 102 may send a data rate change indication to the decoder. Based on the indication, the decoder at the WTRU 102 can generate a CMR and send it to the encoder on the network side.

Both AMR and AMR-WB VoIP codecs support voice activity detection during quiet periods and the generation of comfort noise parameters. Typically, during quiet periods, comfort noise packets are sent from the sender to the receiver. In accordance with the present invention, device 200 can include a comfort noise generator (not shown) to generate comfort noise during quiet periods. Comfort noise is generated at the receiving end without receiving comfort noise packets from the transmitting end. In this way, physical layer resources can be saved during quiet periods.

The UDP layer 204 (preferably the UDP-Lite layer) appends a UDP header (preferably a UDP-Lite header) to the encoded transmission material to generate a UDP packet (preferably a UDP-Lite packet). . UDP-Lite provides UDP variants with increased flexibility in the form of partial checksums. The UDP-Lite header includes a checksum value and a checksum override field. The checksum override field indicates the length of the bit covered by the checksum value in the UDP-Lite header. When the checksum value covers the entire packet (which is the default), UDP-Lite can be semantically identical to UDP. When UDP-Lite is started, the packet is divided into sensitive bits and insensitive bits, and the checksum value is calculated to cover the sensitive bits. At the receiving end, an error in the insensitive bit will not cause the packet to be dropped by the transport layer.

The IP layer 206 generates a transmit VoIP packet from the encoded transmission material by appending an IP header. The IP layer 206 also processes a receive VoIP packet, removes the IP header, and forwards the remainder of the packet to the upper layer.

The header compression and decompression layer 208 compresses the header of the transmitted VoIP packet and decompresses the header of the received VoIP packet. Robust Header Compression (ROHC) is one of many header compression mechanisms. The header compression and decompression layer 208 selectively performs compression and decompression in accordance with instructions from the controller 220. The header compression and decompression layer 208 sends uncompressed headers to reduce error propagation under certain conditions. For example, during handover or when link conditions are poor, controller 220 issues an indication to header compression and decompression layer 208 to transmit the complete header. Controller 220 can be in core network path 120 Medium, or in the WTRU 102 and Node-B 112, respectively.

Alternatively, the header compression and decompression layer 208 can selectively perform compression based on the feedback packets sent by the network entity (e.g., access gateway). The feedback packet indicates the link condition, the need for switching, and the like.

When UDP-Lite is implemented, the network entity (e.g., access gateway, core network path, or VoIP gateway) will send an indication to the header compression and decompression layer 208 indicating whether UDP-Lite is active during the VoIP session. If UDP-Lite is enabled, the checksum override field of the UDP-Lite header is not compressed during header compression. This ensures that the packet has an accurate CRC.

The RLC layer 210 provides sequential transmission of VoIP packets. The RLC layer 210 generates a transmit RLC protocol data unit (PDU) from the transmit VoIP packet and generates a receive VoIP packet from a receive RLC PDU. The VoIP packet is sent on the RLC in no answer mode (UM). The UM RLC provides detection of error data, copy avoidance, and reordering. The RLC layer 210 can perform segmentation of IP packets. In accordance with the present invention, RLC 210 (i.e., UM RLC) sends all packets received from MAC layer 212 to IP layer 206 or header compression and decompression layer 208 along with an indication of whether the packet was successfully received.

The MAC layer 212 provides a data transfer service between communication peer nodes. The MAC layer 212 generates a transmit MAC PDU from the transmit RLC PDU and a receive RLC PDU from a receive MAC PDU. The MAC layer 212 supports different error protection and variable for sensitive and insensitive bits. The size of the packet and the retransmission of the packet during the predetermined time.

The MAC layer 212 can receive an indication from the VoIP codec 202 regarding the number of sensitive bits for each VoIP packet. The MAC layer 212 can divide the VoIP packet into a plurality of equal or unequal segments. The MAC layer 212 appends a separate Loop Redundancy Check (CRC) to each segment. The MAC layer 212 generates segments such that sensitive bits propagate with a minimum number of segments.

If the MAC layer 212 can transmit complex transport blocks (e.g., H-ARQ PDUs) in the same Transmission Time Interval (TTI), then as a different TB, the MAC layer 212 can transmit all or multiple segments in the same TTI. If the MAC layer 212 can only transmit one TB in the TTI, the segment is transmitted in a different TTI. Preferably, a separate CRC is appended to each TB. Different CRCs with different intensities can be attached (eg, a stronger CRC is attached to the TB including the sensitive bits). Alternatively, the CRC can be attached only to the TB including the sensitive bit.

Alternatively, the segmentation can be performed without an explicit indication of the sensitive bit. The VoIP codec 202 outputs its bits in a predetermined order in accordance with sensitivity. For example, VoIP codec 202 may output a bit with higher sensitivity in the last (or first) X bits in the packet (ie, X bits after, for example, the header of the IP header). The MAC layer 212 segments the VoIP packets into N segments and assigns them different robustness according to the order of the segments. For example, if the sensitive bit is at the end of the VoIP packet, the last segment can have the highest error protection. Such a party The advantage of the case is that no explicit signaling is required.

Alternatively, in addition to the MAC layer 212, the RLC layer 210 may perform segmentation of the VoIP packet with or without receiving an explicit indication of the sensitive bit.

The physical layer 214 transmits the transmit MAC PDU via the wireless channel and generates a receive MAC PDU from the received data. The entity layer 214 receives an indication from the MAC layer 212 regarding the segment with sensitive bits. The physical layer 214 then performs lower modulation and better encoding on the segments that include the sensitive bits.

Alternatively, the MAC layer 212 may not segment the transmitting VoIP packet, but may indicate the number and location of sensitive bits to the physical layer 214. The physical layer 214 then performs a better encoding of the sensitive bits (e.g., less puncturing of sensitive bits and/or more repetition of sensitive bits).

The MAC layer 212 includes a MAC-hs 216 and/or a MAC-e/es 218. It should be noted that the terms "hs" and "e/es" are used to denote a particular MAC function, and the invention is not limited to any particular MAC function involving these terms, but is suitable for any MAC function, independent of the sign of a particular MAC function. . The MAC-hs 216 is responsible for the management of physical resources and packet transmission in the downlink of High Speed Downlink Packet Access (HSDPA). The MAC-hs 216 provides fast scheduling and retransmission (if necessary). HSDPA implements asynchronous hybrid automatic repeat request (H-ARQ) processing. The packet is sent (or retransmitted) from the same H-ARQ process at any time. The sending of packets can be based on the priority of the packets.

In the uplink, MAC-e/es 218 provides fast scheduling and retransmission for High Speed Uplink Packet Access (HSUPA). In HSUPA, 4 H-ARQ processes are provided for a 10 msec transmission time interval (TTI) and 8 H-ARQ processes are provided for a 2 msec TTI. The H-ARQ scheme in HSUPA is synchronous H-ARQ. Thus, after the previous transmission, the packets are transmitted (or retransmitted) from the "N" TTIs of the same H-ARQ process, where N = 4 and N = 8 for 10 msec TTI and 2 msec TTI, respectively. Traditional VoIP codecs generate packets every 20msec. To support synchronized H-ARQ, the number of H-ARQ processes can be adjusted to match the VoIP packet generation rate. For example, for a 2 msec TTI, the number of H-ARQ processes can be increased to ten (10) to match the 20 msec VoIP packet generation rate. Alternatively, two or more complex H-ARQ processes separated as far as possible can be allocated for the VoIP service. For example, in the case of eight (8) H-ARQ processing, H-ARQ processes one and five can be assigned to the VoIP service.

Preferably, Node-B 112 can allocate radio resources to the WTRU 102 by transmitting control information. This control information can be sent in the control packet or sent on the control channel. In accordance with the present invention, in order to reduce the control load, radio resources are allocated to the plurality of WTRUs 102 for a predetermined duration while a single control packet is transmitted over a longer duration. The control information covers the plurality of WTRUs 102. The WTRUs 102 in similar channel conditions can be combined together. Since the channel conditions are similar, a similar amount of resources can be allocated, and a similar modulation and coding scheme can be used by the WTRU 102. Group use. For a separate WTRU 102, only the allocated resources and WTRU entities need to be indicated in the control packet. Therefore, the control load is reduced.

In addition, control information can be transmitted periodically (for example, 10 msec or 20 msec). The period for radio resource allocation may be based on codec rate and retransmission possibilities. Due to the periodicity of radio resource allocation, fewer bits can be used for certain control information (eg, scheduling information and WTRU identification).

However, a disadvantage is that if the WTRU 102 does not use the allocated resources, the bandwidth in the uplink is wasted. Therefore, the WTRU 102 should use the resource or control data flow assigned to any other user. In this case, a particular bit is allocated to indicate a change in the control information and/or data flow so that the receiver can learn that the packet is from a different stream and encodes corresponding to the control information.

In 3GPP LTE, the physical layer wireless interface is OFDM MIMO. The radio resources are divided into subcarrier groups. The Node-B 112 periodically assigns subcarrier groups to the WTRU 102. Assuming that each WTRU 102 is periodically allocated the minimum required resources, if the packet size or MCS changes, the periodic resources may not be sufficient. For example, if sent under lower modulation and robust coding, the retransmitted packet can be successfully sent. However, in this case, it is impossible to fit the packet in the allocated resources.

In accordance with the present invention, when a VoIP packet is unsuitable for allocated resources, the WTRU 102 segments the VoIP packet and sends a request for additional resources to the Node-B 112. Figure 3 is an illustration of an embodiment of the present invention A flowchart of a method 300 of transmitting a VoIP packet in the uplink. As described above, the Node-B 112 periodically allocates resources for the uplink and downlink to the plurality of WTRUs 102 (step 302). When the packet is not suitable for the currently allocated resource, the WTRU 102 segments the VoIP packet (step 304) to suit the available resources. The WTRU 102 then transmits the first segment using the currently available resources and also sends a request for additional resources (step 306). The request can be sent by RLC, MAC or entity layer signaling. The additional required resources can be determined by a Transport Format Combination (TFC) selection process. Node-B 112 then temporarily allocates additional resources within a small number of TTIs based on the request (step 308). The WTRU 102 transmits the remaining segments using the additional resources (step 310).

When the Node-B 112 receives the request, the Node-B 112 may successfully receive the first segment or may not successfully receive the first segment. If Node-B 112 successfully receives the first segment, Node-B 112 allocates additional resources to the WTRU so that WTRU 102 transmits the remaining segments using the additional resources. If Node-B 112 does not successfully receive the first segment (assuming the request is part of the physical layer control signaling (eg, H-ARQ associated control signaling)), then Node-B 112 may be a full packet instead of The transmission of the segment allocates resources and sends a negative acknowledgement (NACK) to the WTRU 102. Upon receiving the new resource allocation and NACK, the WTRU 102 may terminate the old H-ARQ transmission and initiate a new H-ARQ transmission to send the complete packet using the new resource instead of the segment.

4 is a diagram for use in an uplink according to another embodiment of the present invention A flow diagram of a method 400 of transmitting a VoIP packet in a link. The Node-B 112 periodically allocates resources for the uplink and downlink to the plurality of WTRUs 102 (step 402). When the packet is not suitable for the currently allocated resource, the WTRU 102 segments the VoIP packet to fit the available resources (step 404). The WTRU 102 then transmits the first segment using the currently available resources without an explicit request for additional resources (step 406). When Node-B 112 receives a segment (rather than a full packet) segment of the packet, Node-B 112 implicitly knows that more resources are needed and additional temporary resources are allocated (step 408). This requires Node-B 112 to decode the MAC header and RLC header to determine which segment is being sent instead of a full packet. The WTRU 102 transmits the remaining segments using additional resources (step 410).

The segmentation and segment information contained in the MAC or RLC header may provide information for determining the amount of temporary resources to be allocated (eg, in a segment/section, the section scheme may provide the total number of sections belonging to the packet, or Provide the total size of the packet).

FIG. 5 is a flow diagram of a method 500 for transmitting a VoIP packet in an uplink in accordance with yet another embodiment of the present invention. The Node-B 112 periodically allocates resources for the uplink and downlink to the plurality of WTRUs 102 (step 502). The WTRU 102 transmits the VoIP packet using the allocated resources (step 504). If it is determined in step 506 that the packet was successfully received, Node-B sends an ACK to the WTRU (step 508) and method 500 ends. If it is determined in step 506 that the packet is not successfully received, Node-B sends NACK to the WTRU (step 510). When the transmission fails, Node-B 112 implicitly knows that the packet will be retransmitted via the H-ARQ mechanism. Accordingly, Node-B 112 allocates additional resources to WTRU 102 without receiving a request for additional resources from WTRU 102 (step 512). The WTRU 102 then transmits the previously failed packet using the additional resources (step 514). The Node-B 112 can perform a soft combination of previously failed transmissions and new transmissions.

6 is a flow diagram of a method 600 for transmitting a VoIP packet in an uplink in accordance with yet another embodiment of the present invention. In this embodiment, synchronous H-ARQ is used between Node-B 112 and the WTRU 102. In synchronous H-ARQ, a retransmission of a previously failed packet is performed after a fixed (time) period of previous transmission. Once the Node-B 112 is licensed, the WTRU 102 uses the resources typically used for synchronous H-ARQ retransmissions as additional temporary resources instead of explicitly allocating additional resources and sending control messages to describe these resources.

The Node-B 112 periodically allocates resources for the uplink and downlink to the plurality of WTRUs 102 (step 602). The WTRU 102 transmits a VoIP packet using the allocated resources (step 604). If it is determined in step 606 that the packet was successfully received, Node-B sends an ACK to the WTRU (step 608) and method 600 ends. If it is determined in step 606 that the packet was not successfully received, Node-B 112 sends a NACK to the WTRU (step 610). The WTRU 102 then segments the packet and the first segment with or without an indication that the WTRU 102 needs more resources (ie, the indication may be hidden as described above) The indications are sent together (step 612). Node-B 112 then returns the license (step 614). The bits used for the grant may be included with the H-ARQ feedback or may be included in the physical layer of the MAC layer signaling. Upon receiving the grant, the WTRU 102 transmits the remaining segments (step 616) using resources for synchronous H-ARQ retransmission (ie, after N TTIs) without requiring temporary resource allocation from the Node-B 112.

In the downlink, if the currently allocated resource is not sufficient to carry the VoIP packet, the Node-B 112 segments the VoIP packet and transmits the first segment using the currently allocated resource. The first paragraph will reduce control information. However, the remaining segments that are not suitable for the current allocated resource are sent along with complete control information (eg, resource allocation, WTRU ID, flow ID, H-ARQ processing ID, etc.). It is also possible to use the same strategy for retransmission of failed packets. The first transmission is sent on the allocated resource. If retransmission is required, the packet to be decoded at the receiving end requires complete control information for the retransmission or the change in the data rate, so the retransmitted packet is sent together with the complete control information.

Example

1. A device that supports VoIP services over a wireless communication network.

2. Apparatus as in embodiment 1, comprising a VoIP codec for encoding the transmitted data and decoding the received data.

3. The apparatus of embodiment 2 wherein the encoding rate of the VoIP codec is specified by the controller.

4. The device of any of embodiments 2-3, wherein the encoding The transmitted data identifies bits that are sensitive to errors and bits that are not sensitive to errors for individual error protection.

5. The apparatus of any of embodiments 2-4, comprising an IP layer for generating a transmit VoIP packet by attaching an IP header to the encoded transmit material, and for processing a receive VoIP Packet.

6. The apparatus of any of embodiments 2-5, comprising an RLC layer for sequential transmission of the transmitting VoIP packet and the receiving VoIP packet.

7. The apparatus of any of embodiments 5-6, comprising a MAC layer for transmitting the transmitting VoIP packet and the receiving VoIP packet between communication peer nodes.

8. The apparatus of any of embodiments 5-7, comprising a physical layer for transmitting the transmitting VoIP packet and receiving the received VoIP packet via a wireless channel.

9. The apparatus of any one of embodiments 2-8 wherein the VoIP codec sends an explicit indication of error sensitive bits and error insensitive bits to separately handle sensitive bits and not Sensitive bits for error protection.

10. The apparatus of any one of embodiments 2-8, wherein the VoIP codec outputs the transmitted data in a predetermined order according to sensitivity to errors, thereby separately processing the sensitive bit and the insensitive bit to Used for error protection.

11. The apparatus of any one of embodiments 7-10, wherein one of the RLC layer and the MAC layer divides the transmitting VoIP packet into a plurality of segments, thereby Handle sensitive and insensitive bits for error protection.

12. The apparatus of embodiment 11 wherein the MAC layer employs a more robust modulation and coding scheme for segments comprising sensitive bits.

13. The apparatus of any of embodiments 11-12, wherein one of the RLC layer and the MAC layer divides the transmit VoIP packet into a plurality of segments such that the number of segments including the sensitive bit is as small as possible.

14. The apparatus of any of embodiments 11-13, wherein the MAC layer appends a separate CRC to each segment.

The apparatus of any of embodiments 11-14, wherein the MAC layer is configured to transmit a plurality of TBs in the same TTI and to transmit each segment via a separate TB having a separate CRC.

The apparatus of any of embodiments 11-14, wherein the MAC layer is configured to transmit one TB in the TTI and to transmit each segment in a different TTI.

The apparatus of any of embodiments 11-15, wherein the MAC layer appends the CRC only to the segment comprising the sensitive bit.

The apparatus of any of embodiments 11-17, wherein the MAC layer appends a CRC having a higher strength in terms of error protection to the segment including the sensitive bit.

The apparatus of any of embodiments 11-18, wherein the sensitive bit and the insensitive bit are separately processed via the physical layer for error protection.

20. The apparatus of embodiment 19 wherein the MAC layer is about sensitive bits An indication of the number and location is sent to the physical layer.

The apparatus of any one of embodiments 19-20, wherein the physical layer employs less puncturing of the sensitive bits.

22. The apparatus of any one of embodiments 19-21 wherein the physical layer employs more repetitions of sensitive bits.

23. The apparatus of any one of embodiments 5-22, further comprising a header compression and decompression entity for compressing a header of the VoIP packet to be transmitted and for performing a header of the received VoIP packet unzip.

The apparatus of embodiment 23, wherein the header compression and decompression entity selectively performs compression and decompression in accordance with an indication from the controller.

The apparatus of any one of embodiments 23-24 wherein the header compression and decompression entity selectively performs compression and decompression based on feedback from the network entity regarding wireless channel conditions.

26. The apparatus of any of embodiments 4-25, further comprising a UDP layer for attaching and removing UDP-Lite headers, the UDP-Lite header including a section for partially covering sensitive bits Check and cover the field.

27. The apparatus of embodiment 26, further comprising a header compression and decompression entity for compressing a header of the transmit VoIp packet and decompressing a header of the received VoIP packet, wherein the controller An indication of whether UDP-Lite is started is sent to the header compression and decompression entity so that when UDP-Lite is started, the checksum coverage field of the UDP-Lite header is not compressed.

The apparatus of any of embodiments 3-27, wherein the controller transmits the CMR to adjust the encoding rate.

The apparatus of any of embodiments 3-27, wherein the controller sends an indication indicative of a requirement for adjusting the encoding rate, and the CMR is sent to the communication peer node in response to the indication.

The device of any of embodiments 3-29, wherein the controller is in the WTRU.

The device of any of embodiments 3-29, wherein the controller is in Node-B.

The device of any of embodiments 3-29, wherein the controller is in the aGW.

The apparatus of any of embodiments 3-29 wherein the controller is located in a core network way entity.

The device of any of embodiments 3-29, wherein the controller is located in the RNC.

35. Apparatus according to any of embodiments 1 to 34, comprising a comfort noise generator for generating comfort noise for quietness without receiving comfort noise packets from a communication peer node Comfort noise is generated during the period.

The apparatus of any one of embodiments 6-35, wherein the RLC layer transmits all packets having an indication of whether the packet was successfully received.

The apparatus of any one of embodiments 7-36, wherein the MAC layer comprises complex H-ARQ processing and implements synchronous H-ARQ.

38. The apparatus of embodiment 37, wherein at least two H-ARQ processes in the complex H-ARQ process are allocated for the VoIP service such that the allocated H-ARQ process is separated as far as possible.

The device of any one of embodiments 5-38, wherein if the transmitting VoIP packet is not suitable for the currently allocated radio resource, the VoIP packet is divided into at least two segments, thereby transmitting the transmitting VoIP packet in segments. .

40. The apparatus of embodiment 39, wherein the MAC layer transmits a request for additional radio resources with the first segment and transmits the remaining segments using the additional radio resource.

The apparatus of any one of embodiments 2-40, wherein the wireless resources are periodically allocated.

The apparatus of embodiment 41 wherein the minimum wireless resource is periodically allocated.

The apparatus of any one of embodiments 40-42, wherein the MAC layer transmits the remaining segments using additional radio resources that are subsequently allocated to the device once the first segment is transmitted.

The apparatus of any one of embodiments 40-42 wherein the remaining segments are allocated additional radio resources.

The apparatus of any one of embodiments 40-42 wherein the additional VoIP packets are allocated additional radio resources.

46. The apparatus of embodiment 39, wherein the MAC layer transmits the remaining segments using radio resources allocated for packetized synchronous H-ARQ retransmissions.

47. The apparatus of embodiment 46 wherein the VoIP packet is a retransmission of a previously failed packet.

The apparatus of embodiment 47, wherein the MAC layer uses the additional radio resource to transmit a retransmission of a previously failed packet.

49. A method of supporting VoIP services over a wireless communication network.

50. The method of embodiment 49, comprising encoding the data, wherein the encoding rate is specified by the controller.

51. The method of embodiment 50, comprising identifying sensitive bits and insensitive bits in the encoded data.

The method of any one of embodiments 50-51, comprising generating a VoIP packet by appending an IP header to the encoded material.

53. The method of embodiment 52, comprising processing the VoIP packet for error protection, wherein error protection is performed separately on the sensitive bit and the insensitive bit.

54. The method of embodiment 53, comprising transmitting the VoIP packet.

The method of any one of embodiments 51-54, wherein the explicit indication of the bit sensitive to the error and the bit insensitive to the error is sent to separately handle the sensitive bit and the insensitive bit Yuan for use in error protection.

The method of any one of embodiments 51-54, wherein the encoded data is arranged in a predetermined order according to sensitivity to errors, thereby separately processing the sensitive bit and the insensitive bit for error protection .

57. The method of any of embodiments 52-56, further comprising VoIP packets are divided into complex segments to handle sensitive and insensitive bits separately for error protection.

The method of embodiment 57 wherein the VoIP packet is segmented by the RLC layer.

The method of embodiment 57 wherein the VoIP packet is segmented by the MAC layer.

The method of any one of embodiments 56-59, wherein the MAC layer employs a more robust modulation and coding scheme for segments comprising sensitive bits.

The method of any one of embodiments 57-60, wherein the VoIP packet is segmented such that the number of segments comprising the sensitive bit is as small as possible.

62. The method of any of embodiments 57-61, further comprising appending a separate CRC to each segment.

The method of embodiment 62, wherein the MAC layer is configured to transmit a plurality of TBs in the same TTI and to transmit each segment via a separate TB having a separate CRC.

The method of embodiment 62 wherein the MAC layer is configured to transmit one TB in the TTI and to transmit each segment in a different TTI.

The method of any of embodiments 53-64, wherein the CRC is only attached to the segment comprising the sensitive bit.

The method of any of embodiments 53-65, wherein the CRC having a higher strength in terms of error protection is appended to the segment comprising the sensitive bit.

The method of any one of embodiments 53-66, wherein the physical layer processes the sensitive bit and the insensitive bit separately for error protection.

The method of embodiment 67, wherein the MAC layer sends an indication of the number and location of the sensitive bits to the physical layer.

The method of any one of embodiments 67-68, wherein the physical layer employs less puncturing of the sensitive bits.

The method of any one of embodiments 67-69, wherein the physical layer employs more repetitions of the sensitive bits.

71. The method of any of embodiments 52-70, further comprising compressing a header of the VoIP packet.

The method of embodiment 71, wherein the compressing is selectively performed in accordance with an indication from the controller.

The method of any one of embodiments 71-72, wherein the compressing is selectively performed based on feedback related to wireless channel conditions from the network entity.

The method of any one of embodiments 55-73, further comprising an additional UDP-Lite header, the UDP-Lite header including a checksum coverage field for partially overwriting the sensitive bit.

75. The method of embodiment 74, further comprising the controller transmitting an indication of whether UDP-Lite is initiated, such that when UDP-Lite is initiated, the checksum coverage field of the UDP-Lite header is not compressed .

The method of any one of embodiments 50-75, wherein the controller Send CMR to adjust the encoding rate.

The method of any one of embodiments 50-75, wherein the controller sends an indication indicative of a requirement for adjusting the encoding rate and transmits the CMR to the communication peer node in response to the indication.

The method of any one of embodiments 50-77 wherein the controller is in the WTRU.

The method of any one of embodiments 50-77, wherein the controller is in Node-B.

The method of any one of embodiments 50-77, wherein the controller is in the aGW.

The method of any one of embodiments 50-77 wherein the controller is located in the RNC.

The method of any one of embodiments 50-77, wherein the controller is located in a core network way entity.

The method of any one of embodiments 54-82, further comprising receiving a VoIP packet.

84. The method of embodiment 83, comprising processing the received VoIP packet for recovering VoIP material.

85. The method of embodiment 84, comprising generating comfort noise during quiet periods without receiving a comfort noise packet.

The method of any one of embodiments 83-85, further comprising: transmitting the received VoIP packet having an indication of whether the VoIP packet was successfully received Send to the upper level.

The method of any of embodiments 54-86, further comprising performing a synchronous H-ARQ mechanism for transmission and retransmission of VoIP packets.

The method of embodiment 71, wherein the VoIP service is allocated at least two H-ARQ processes in the complex H-ARQ process such that the allocated H-ARQ process is separated as far as possible.

The method of any one of embodiments 52-88, further comprising dividing the VoIP packet into at least two segments if the VoIP packet is not suitable for the currently allocated radio resource, thereby transmitting the VoIP packet in segments.

90. The method of embodiment 89, further comprising transmitting a request for additional wireless resources with the first segment to use the additional wireless resource to transmit the remaining segments.

The method of any one of embodiments 50-90, wherein the wireless resources are periodically allocated.

The method of embodiment 91 wherein the minimum wireless resource is periodically allocated.

The method of any one of embodiments 89-92 wherein, upon receiving the first segment, the additional radio resources are allocated to transmit the remaining segments by using the additional radio resources.

The method of any one of embodiments 90-93, wherein the remaining segments are allocated additional radio resources.

The method of any one of embodiments 90-93, wherein The VoIP packet allocates additional wireless resources.

The method of any one of embodiments 90-95, wherein the remaining segments are transmitted using radio resources allocated for synchronous H-ARQ retransmission of VoIP packets.

The method of embodiment 96 wherein the VoIP packet is a retransmission of a previously failed packet.

The method of embodiment 97 wherein the previously failed VoIP packet is retransmitted via the use of additional radio resources.

99. A system for supporting VoIP services over a wireless communication network.

100. The system of embodiment 99, comprising a plurality of WTRUs configured to transmit VoIP packets.

101. The system of embodiment 100, comprising a Node-B, configured to packetize WTRUs in similar conditions and periodically allocate radio resources to the WTRU group for a predetermined duration.

102. The system of any one of embodiments 99-101, comprising a core network path for transmitting the transmitting VoIP packet and the receiving VoIP packet.

The system of any one of embodiments 101-102, wherein the period for radio resource allocation is based on a codec rate and a retransmission probability.

The system of any one of embodiments 100-103, wherein the WTRU includes a particular bit in the VoIP packet to indicate a change in control information and data flow.

The system of any one of embodiments 100-104, wherein If the VoIP packet is not suitable for the currently allocated radio resource, the WTRU divides the VoIP into at least two segments, thereby transmitting the VoIP packet in segments.

The system of any one of embodiments 101-105, wherein the Node-B allocates a minimum radio resource to each WTRU.

The system of any one of embodiments 105-106, wherein, upon receiving the first segment, the additional wireless resources are allocated to transmit the remaining segments by using the additional wireless resources.

The system of embodiment 107, wherein the remaining segments are transmitted using radio resources allocated for synchronous H-ARQ retransmission of the VoIP packet.

The system of any one of embodiments 105-106, wherein the WTRU sends a request for additional radio resources to the Node-B along with the first segment, the Node-B allocates additional radio resources, and the WTRU uses The additional radio resource sends the remaining segments.

The system of embodiment 109, wherein the remaining segments are allocated additional radio resources.

The system of embodiment 109, wherein the additional VoIP packets are allocated additional radio resources.

The system of any one of embodiments 101-106, wherein upon receiving the failed VoIP packet, the Node-B allocates additional radio resources such that the WTRU retransmits a previous by using the additional radio resource Failed VoIP packet.

Although the features and elements of the present invention are in a preferred embodiment The description is made with specific combinations, but each feature or element may be used alone or in combination with other features and elements of the present invention without the other features and elements of the preferred embodiment. Use in case.

200‧‧‧ device

MAC‧‧‧Media Access Control

RLC‧‧‧Wireless Link Control

UDP‧‧‧ User Data Packet Agreement

Voice of VoIP‧‧‧Internet Protocol

Claims (20)

A WTRU consists of: a receiver configured to receive a resource allocation, wherein the resource allocation is for periodic transmission of uplink data and the resource allocation indicates a period to be used for uplink data a subcarrier that is transmitted; and a transmitter configured to transmit Voice over Internet Protocol (VoIP) data using the resource allocation; in the event that the VoIP material is not successfully transmitted, the receiver is further configured to : receiving a negative acknowledgment; and receiving a new resource allocation; and the transmitter is further configured to retransmit the VoIP data using the new resource allocation. The wireless transmission/reception unit according to claim 1, wherein the WTRU is a long term evolution project WTRU. A WTRU according to claim 1, wherein a VoIP packet is segmented and transmitted in a plurality of segments. The WTRU of claim 1, wherein the transmitter is further configured to transmit a physical layer signal indicating that an additional uplink resource is required. The WTRU of claim 1, wherein the transmitter is further configured to transmit a media access control message having the VoIP data indicating an additional uplink resource required. A method of using in a WTRU, comprising: receiving a resource allocation, wherein the resource allocation is for periodic transmission of uplink data and the resource allocation indicates periodic transmission to be used for uplink data Subcarriers; and use the resource allocation to transmit Voice over Internet Protocol (VoIP) data; receive a negative acknowledgment if the VoIP data is not successfully transmitted; receive a new resource allocation; Retransmit the VoIP data using this new resource allocation. The method of claim 6, wherein the transmitting comprises: segmenting a VoIP packet and transmitting the VoIP packet in a plurality of segments. The method of claim 6, further comprising: transmitting a physical layer signal indicating that an additional uplink resource is required. The method of claim 6, further comprising: transmitting a media access control message having the VoIP data indicating that the additional uplink resource is required. The method of claim 6, wherein the WTRU is a long term evolution project WTRU. A base station includes: a transmitter configured to transmit a resource to be assigned to a wireless transmission/connection a receiving unit, wherein the resource allocation is for periodic transmission of uplink data and the resource allocation represents a subcarrier to be used for periodic transmission of uplink data; and a receiver configured to use the resource allocation Receiving voice over internet protocol (VoIP) data; in the event that the VoIP data is not successfully received, the transmitter is further configured to: transmit a negative acknowledgment; and transmit a new resource allocation; and receive The device is further configured to receive the VoIP data using the new resource allocation. For example, the base station described in claim 11 of the patent scope, wherein the base station is a long-term evolution project base station. A base station as described in claim 11, wherein a VoIP packet is segmented and received in a plurality of segments. The base station of claim 11, wherein the receiver is further configured to receive a physical layer signal indicating that an additional uplink resource is required. The base station of claim 11, wherein the receiver is further configured to receive a media access control message having the VoIP data indicating that an additional uplink resource is required. A method of using a base station, comprising: Transmitting a resource to a WTRU, wherein the resource allocation is for periodic transmission of uplink data and the resource allocation represents subcarriers to be used for periodic transmission of uplink data; and using the Resource allocation receives voice over internet protocol (VoIP) data; transmits a negative acknowledgment if the VoIP data is not successfully received; transmits a new resource allocation; and receives the new resource allocation using the new resource The VoIP material. The method of claim 16, wherein the receiving the VoIP data comprises: segmenting a VoIP packet and receiving the VoIP packet in a plurality of segments. The method of claim 16, further comprising: receiving a physical layer signal indicating that an additional uplink resource is required. The method of claim 16, further comprising: receiving a media access control message having the VoIP data indicating that the additional uplink resource is required. For example, the method described in claim 16 wherein the base station is a long-term evolution project base station.