Patent Publication Number: US-2013250853-A1

Title: Methods and apparatuses to improve round trip time in transfer control protocol using accelerated acknowledgement messages

Description:
CLAIM OF PRIORITY UNDER 35 U.S.C. §119 
     The present application for patent claims priority to Provisional Application No. 61/613,084 entitled “Methods and Apparatuses to Improve Round Trip Time in Transfer Control Protocol Using Accelerated Acknowledgement Messages” filed Mar. 20, 2012, and assigned to the assignee hereof and hereby expressly incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Field 
     Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to optimizing transfer control protocol (TCP) acknowledgement transmission in a slow-start process. 
     2. Background 
     Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. One example of such a network is the UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology supported by the 3rd Generation Partnership Project (3GPP). The UMTS, which is the successor to Global System for Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-Code Division Multiple Access (W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), and Time Division-Synchronous Code Division Multiple Access (TD-SCDMA). The UMTS also supports enhanced 3G data communications protocols, such as High Speed Packet Access (HSPA), which provides higher data transfer speeds and capacity to associated UMTS networks. 
     As the demand for mobile broadband access continues to increase, research and development continue to advance the UMTS technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications. 
     TCP is the predominant transport layer protocol in UMTS. TCP utilizes internet protocol (IP) as the network layer. TCP provides a connection-oriented, reliable, byte stream service to the application layer running on top of TCP, wherein “connection-oriented” means that the two end-point devices using TCP must establish a connection with each other before they are able to exchange data. TCP uses sequence numbers to achieve reliability. When TCP sends a segment, it maintains a timer, waiting for the other end to acknowledge reception of the segment. Where the acknowledgement is not received in time, the segment is retransmitted. Whenever a timer at the sender times out waiting for an acknowledgement, the sender changes the congestion window to one segment and starts a “slow-start process.” Furthermore, whenever a TCP end-point starts with the slow-start process, it takes several round-trip times to ramp up to the full capacity of the link. Typically, a time-out is associated with congestion in the network. This is often true in a wired network, which necessitates starting the congestion window at one segment, because this provides the network time to clear any outstanding packets causing the congestion. In a wireless system, however, the timeout is more likely due to loss of the packet than due to congestion. Additionally, the round-trip times in a wireless system are orders of magnitude higher than in a wired network. Because of this, whenever a TCP end-point starts with the slow-start process in a wireless network, the slow-start process may have a significant impact on overall user experience. 
     To avoid sender time-outs due to missing acknowledgements, Wireless Wide Area Networks (WWANs) have a link layer protocol that ensures reliability: the Radio Link Control (RLC). This protocol provides reliability in a WCDMA system and hides the TCP/IP layer from packet losses. In operation, a TCP/IP packet is chopped up into one or more RLC PDUs by the sending RLC entity. The RLC layer maintains its own sequence numbers and acknowledgements. When an acknowledgement is not received by the sending RLC radio network controller (RNC) or a negative acknowledgement is received, the RNC retransmits the RLC packet. One of the purposes of utilizing the RLC layer is to hide the TCP layer from wireless media access control (MAC) layer errors. A typical wireless system is configured to have certain error rates at the MAC layer to strike a balance between achieving reliability versus scalability in terms of number of users supported. For example, if the MAC layer is configured to have a one percent block error rate (BLER), then one percent of the packets are not successfully decoded by the receiver. These unsuccessfully-decoded packets go through RLC layer retransmissions. Without an RLC layer and its retransmissions, these one percent of packets would result in TCP time-outs, which would have an adverse impact on the TCP user experience. Thus, the RLC layer hides the TCP layer from TCP timeouts and retransmissions. However, since there can be multiple transmissions and/or retransmissions at the RLC layer to send the RLC packets that make up the TCP packet, such multiple transmissions or retransmissions change a timing of when a TCP acknowledgement is transmitted to and received at the server. In other words, the TCP acknowledgement is not sent to the server until all of the RLC packets making up the TCP packet are acknowledged. So, the multiple transmissions and/or retransmissions introduce what is called Round Trip Time (RTT) fluctuations. This may potentially have severe impact on the overall performance of TCP and end-user-experience. 
     Furthermore, the RTT fluctuations affect the slow-start process. The slow-start process operates by setting the rate at which new packets are to be injected into the network to the rate at which the acknowledgements are returned by the receiving device, for example, a user equipment (UE). In addition, the slow-start process adds another window to the TCP of the sender: the congestion window. When a new connection is established with a host on another network, the congestion window is initialized to one segment. Each time an acknowledgement message (ACK) is received, the congestion window is increased by one segment. The sender can transmit a number of segments up to the minimum of the congestion window and the advertised window. The congestion window is flow control imposed by the sender, while the advertised window is flow control imposed by the receiver. 
     In operation of the slow-start process, the sender begins by transmitting a number of segments equal to an initial window size and waiting for the ACK. When that ACK is received, the congestion window is incremented by the initial window size and twice the number of segments as that of the initial window size can be sent. For example, with an initial window size of one segment and an increased window size of two segments, when both of these segments are acknowledged, the congestion window may be increased by four times, which may correspond to an exponential increase. This exponential increase happens until the congestion window reaches a threshold value. Once the congestion window crosses this threshold value, a congestion avoidance algorithm is utilized and a congestion avoidance phase is initiated. During such a congestion avoidance phase, the congestion window (“cwnd”) is incremented by 1/cwnd each time an ACK is received. Thus, this is an additive increase, compared to the exponential increase associated with the slow-start process. 
     For example, assuming that the initial threshold value is 65,535 bytes and the Maximum Segment Size (MSS) is around 1500 bytes, it takes six round-trips to reach the threshold value and for the congestion avoidance algorithm to be initiated. During the slow-start process, the link capacity is not fully utilized. For example, where the round trip time to the server is around 100 ms then it takes more than half a second before the link can be fully utilized. In a web-browsing session each time a user requests a page, a new TCP connection is established. Since an average web-page is around 300 KB in size, much more time is spent in the TCP slow-start process than in the congestion avoidance phase. Therefore, methods and apparatuses for reducing time in the slow-start process by reducing round trip time for TCP packets are desired to improve the overall user experience. 
     SUMMARY 
     The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. 
     The present disclosure presents methods and apparatuses for optimizing TCP acknowledgement transmission in a TCP slow-start process in a wireless communication environment. For example, in an aspect, the present disclosure presents a method of wireless communication, which may include receiving, at a radio network controller, a transmission control protocol packet for a user equipment from a server. Furthermore, example methods may include reforming the TCP packet into a set of radio link control packets, transmitting the set of RLC packets to a base station, and sending an accelerated TCP acknowledgement message to the server based on the transmitting of the set of RLC packets to the base station. 
     Additionally, the present disclosure presents an apparatus for wireless communication, which may include means receiving, at a radio network controller, a transmission control protocol packet for a user equipment from a server. In addition, the apparatus may include means for reforming the TCP packet into a set of radio link control packets, means for transmitting the set of RLC packets to a base station, and/or means for sending an accelerated TCP acknowledgement message to the server based on the means for transmitting the set of RLC packets to the base station. 
     In an additional aspect, the present disclosure describes a computer program product, which may include a computer-readable medium that includes code for receiving, at a radio network controller, a transmission control protocol packet for a user equipment from a server. Additionally, the computer-readable medium may include code for reforming the TCP packet into a set of radio link control packets, code for transmitting the set of RLC packets to a base station, and/or code for sending an accelerated TCP acknowledgement message to the server based on the transmitting the set of RLC packets to the base station. 
     Furthermore, the present disclosure presents an apparatus for wireless communication, which may include at least one processor and a memory coupled to theat least one processor, where the at least one processor is configured to receive, at a radio network controller, a transmission control protocol packet for a user equipment from a server. In addition, the at least one processor may be configured to reform the TCP packet into a set of radio link control packets, transmit the set of RLC packets to a base station, and send an accelerated TCP acknowledgement message to the server based on the transmitting the set of RLC packets to the base station. 
     These and other aspects of the disclosure will become more fully understood upon a review of the detailed description, which follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a system-level diagram illustrating devices for improving round trip time for an optimized slow-start process in TCP in a wireless system; 
         FIG. 2  is a block diagram of a generic computer device according to aspects of the current description; 
         FIG. 3  is a flow chart of an example methodology for decreasing round trip time for TCP packets in a wireless system; 
         FIG. 4  is a flow chart of a further aspect of the methodology of  FIG. 3 ; 
         FIG. 5  is a message flow diagram of an example use case according to aspects of the current description; 
         FIG. 6  is an electrical component block diagram according to aspects of the present disclosure; 
         FIG. 7  is a block diagram illustrating an example of a hardware implementation for an apparatus employing a processing system; 
         FIG. 8  is a block diagram conceptually illustrating an example of a telecommunications system; 
         FIG. 9  is a conceptual diagram illustrating an example of an access network. 
         FIG. 10  is a conceptual diagram illustrating an example of a radio protocol architecture for the user and control plane; and 
         FIG. 11  is a block diagram conceptually illustrating an example of a Node B in communication with a UE in a telecommunications system. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts. 
     According to the present disclosure, the round trip time (RTT) for TCP packets may be lessened, for example, to improve a TCP slow-start process in UMTS. In an aspect, a radio network controller (RNC) may establish a TCP session with a server and one or more base stations and/or user equipment in a wireless environment. As noted above, the round trip time of a TCP packet may be detrimentally extended by RLC level multiple transmissions and/or retransmission of data packets from the RLC layer to the one or more UEs through the base station. Because the RTT of packets is defined at the time from the initial transmission of the TCP packet from the server to the time of receipt of an acknowledgement of correct reception and decoding of the TCP packet from the UE at the server, generating an “accelerated” TCP acknowledgement (ACK) message at the RNC and transmitting this accelerated TCP ACK to the server may reduce RTT. Such an accelerated TCP ACK may also be referred to as a fake TCP ACK. For example, in an aspect of the present disclosure, the RNC may generate the accelerated TCP ACK at the time that the TCP packet has been broken down into multiple RLC packets and these RLC packets are sent to a base station for transmission to a UE. Specifically, transmitting such an accelerated TCP ACK before the UE correctly receives all RLC packets, generates a TCP acknowledgement message, and sends the TCP acknowledgement message to the RNC for forwarding to the server, will speed up the slow-start process by negating round trip time delay that may occur due to multiple transmissions and/or retransmissions of RLC packets between the RNC and the destination UE. Thus, by speeding up the slow-start process, the network gets to the full pipe stage faster, e.g., is able to more quickly utilize the full link capacity, which may improve the overall user experience. 
     Referring to  FIG. 1 , a wireless communication system  1  is illustrated that enables reduction of round trip time (RTT) in packet communication and an ability to more quickly utilize a full link capacity in a TCP slow-start process. System  1  may include, for example, a server  1000 , a radio network controller (RNC)  2000 , and one or more base stations  3000  that may serve one or more user equipment (UE)  4000 . In an aspect, server  1000  may generate, store, transmit, and/or receive one or more TCP packets  1004  in TCP component  1002 . In an aspect, though not shown explicitly in  FIG. 1 , server  1000  may receive TCP packets  1004  from a core network. Furthermore, server  1000  may communicate with RNC  2000  via communication link  10 . 
     In addition, system  1  may include RNC  2000 , which may be configured to receive TCP packet  1004  and send a corresponding accelerated TCP acknowledgement message  2006  to server  1000 . According to the present disclosure, the accelerated TCP acknowledgement  2006  is termed “accelerated” because the accelerated TCP message according to the present disclosure may be sent before a destination UE receives, decodes, and sends an acknowledgement for the TCP packet, which is the legacy TCP acknowledgement procedure. In an aspect, RNC  2000  may include a message controller  2002 , which may be configured to receive, transmit, process, and/or control TCP and/or RLC messages or packets. Additionally, message controller  2002  may include an accelerated TCP acknowledgement (ACK) component  2004 , which may be configured to generate and transmit the accelerated TCP acknowledgement message  2006  to, for example, server  1000 . In a further aspect, message controller  2002  may include a TCP packet reforming component  2008 , which may be configured to reform the received and stored TCP packet  1004  by breaking down or disassembling the TCP packet  1004  and forming a set of RLC packets  2012  from the disassembled TCP packet  1004 . In an aspect, the set of RLC packets  2012  may be sent to a destination UE (e.g., UE  4000 ) once the set of RLC packets  2012  is formed. 
     Furthermore, RNC  2000  may include a memory  2014 , which may store a window size parameter  2016  and/or previously-received and/or processed TCP packets  2018 . In an aspect, window size parameter  2016  includes a previously-determined window size parameter. For instance, one example that should not be construed as limiting, message controller  2002  of RNC  2000  is configured to intercept or otherwise monitor a TCP connection establishment phase between server  1000  and UE  4000  and store an initial UE advertised window size parameter sent by UE  4000  during the TCP connection establishment phase. As such, in this case, the previously-determined window size parameter is the initial UE advertised window size parameter, which RNC  2000  and/or message controller  2002  may use when sending an initial accelerated TCP acknowledgement message  2006  to server  1000 . In another example that should not be construed as limiting, message controller  2002  of RNC  2000  may receive a TCP acknowledgement message corresponding to previous TCP packet  2018  from base station  3000  and/or UE  4000 , which may include a window size parameter. In an aspect, for example, the previous TCP packet  2018  in this case may be the most recent TCP packet prior to current TCP packet  1004 . As such, in this case, the previously-determined window size parameter is the window size parameter from the TCP acknowledgement message corresponding to previous TCP packet  2018 , which RNC  2000  and/or message controller  2002  may use when sending a subsequent accelerated TCP acknowledgement message  2006  to server  1000 . Furthermore, the stored ones of previous TCP packets  2018  may be utilized in retransmission processes and/or after an RLC reset procedure to ensure that TCP packets not received by the UE  4000  may be retransmitted thereto. For example, in an aspect, RNC  2000  and/or an RLC layer thereof may be set to operate according to the RLC reset procedure configured to re-initiate retransmissions of an RLC packet when a configured maximum number of transmissions of the RLC packet is reached. Moreover, RNC  2000  may be further configured to send the accelerated TCP acknowledgement message  2006  based on the operating of the RLC layer according to the RLC reset procedure. 
     In addition, system  1  may include base station  3000 , which may be configured to receive one or more signals, which may include a set of RLC packets  2012  transmitted by RNC  2000  via communication link  11 . Base station  3000  may forward the set of RLC packets  2012  to user equipment  4000 . Furthermore, base station  3000  may be configured to receive RLC ACK and/or not-acknowledged (NACK) messages, as well as TCP acknowledgement messages, from user equipment  4000  over communication link  12  and may forward these messages to RNC  2000  over communication link  11 . For example, the RLC ACK/NACK messages relate to each of the sets of RLC packets  2012 , while the TCP acknowledgement messages relate to reception of the full set of RLC packets  2012 , e.g. the TCP packet  1004 . 
     In a further aspect, system  1  may include user equipment (UE)  4000 , which may be configured to receive, decode, validate, concatenate, and/or otherwise process one or more RLC packets from a set of RLC packets  2012  transmitted by RNC  2000 . For example, UE  4000  may include a packet validation component  4002 , which may be configured to decode and process each packet in a set of RLC packets  2012  transmitted by RNC  2000 . Where UE  4000  determines that a packet has been correctly received, packet validation component  4002  may transmit an acknowledgement message (ACK)  4004  to base station  3000  for forwarding to RNC  2000 . For example, in one aspect, ACK  4004  may be an RLC ACK to acknowledge receipt of one of the set of RLC packets  2012 , while in another aspect ACK  4004  may a TCP ACK to acknowledge receipt of the full set of RLC packets  2012 , e.g. the TCP packet  1004 . Conversely, where packet validation component  4002  determines that a packet has not been correctly received, packet validation component  4002  may transmit a NACK message  4006  to base station  3000  for forwarding to RNC  2000 . For example, in one aspect, NACK  4006  may be an RLC NACK to indicate that one of the set of RLC packets  2012  has not been received. In addition, packet validation component  4002  may be configured to transmit a window size parameter  2016 , for example in ACK message  4004 , e.g. in the TCP packet ACK, which also may be referred to as a UE acknowledgement message. Specifically, in an aspect, packet validation component  4002  may transmit ACK message  4004  including window size parameter  2016  to base station  3000  for forwarding to RNC  2000  when UE  4000  determines that all packets corresponding to a full TCP packet, e.g. the full set of RLC packets  2012 , have been correctly received by UE  4000 . Thus, in an aspect, window size parameter  2016  may be included with TCP acknowledgement data in a UE acknowledgement message, e.g. TCP version of ACK message  4004 , which may be stored by RNC  2000  for use inclusion in a next accelerated TCP acknowledgement message upon receipt of a subsequent TCP packet from server  1000 . 
     Furthermore, UE  4000  may include concatenating component  4008 , which may be configured to concatenate the set of RLC packets  2012  received from RNC  2000  through base station  3000  to at least partially form TCP packet  1004  originally transmitted from server  1000 . In an aspect, where the concatenation performed by concatenating component  4008  results in a fully- and correctly-received TCP packet composed of the set of RLC packets  2012 , packet validation component  4002  may transmit a UE acknowledgement message, such as a TCP version of ACK  4004 , to RNC  2000  through base station  3000 . 
     Referring to  FIG. 2 , in one aspect, any of server  1000 , RNC  2000 , base station  3000 , and UE  4000  ( FIG. 1 ) may be represented by a specially programmed or configured computer device  20 . Computer device  20  includes a processor  21  for carrying out processing functions associated with one or more of components and functions described herein. Processor  21  can include a single or multiple set of processors or multi-core processors. Moreover, processor  21  can be implemented as an integrated processing system and/or a distributed processing system. 
     Computer device  20  further includes a memory  22 , such as for storing data used herein and/or local versions of applications being executed by processor  21 . Memory  22  can include any type of memory usable by a computer, such as random access memory (RAM), read only memory (ROM), tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof. 
     Further, computer device  20  includes a communications component  23  that provides for establishing and maintaining communications with one or more parties utilizing hardware, software, and services as described herein. Communications component  23  may carry communications between components on computer device  20 , as well as between computer device  20  and external devices, such as devices located across a communications network and/or devices serially or locally connected to computer device  20 . For example, communications component  23  may include one or more buses, and may further include transmit chain components and receive chain components associated with a transmitter and receiver, respectively, or a transceiver, operable for interfacing with external devices. In an additional aspect, communications component  23  may be configured to receive one or more pages from one or more subscriber networks. In a further aspect, such a page may correspond to the second subscription and may be received via the first technology type communication services. 
     Additionally, computer device  20  may further include a data store  24 , which can be any suitable combination of hardware and/or software, that provides for mass storage of information, databases, and programs employed in connection with aspects described herein. For example, data store  24  may be a data repository for applications not currently being executed by processor  21 . 
     Computer device  20  may additionally include a user interface component  25  operable to receive inputs from a user of computer device  20 , and further operable to generate outputs for presentation to the user. User interface component  25  may include one or more input devices, including but not limited to a keyboard, a number pad, a mouse, a touch-sensitive display, a navigation key, a function key, a microphone, a voice recognition component, any other mechanism capable of receiving an input from a user, or any combination thereof. Further, user interface component  25  may include one or more output devices, including but not limited to a display, a speaker, a haptic feedback mechanism, a printer, any other mechanism capable of presenting an output to a user, or any combination thereof. In an additional aspect, a user using the user interface  25  may set one of a first subscription or a second subscription as a dedicated data service (DDS) for the computer device  20 . 
     In a network device implementation, such as for RNC  2000  of  FIG. 1 , computer device  20  may include message controller  2002 , such as in specially programmed computer readable instructions or code, firmware, hardware, or some combination thereof. Further, in another network device implementation, such as for server  1000  of  FIG. 1 , computer device  20  may include TCP component  1002 , such as in specially programmed computer readable instructions or code, firmware, hardware, or some combination thereof. Additionally, in a mobile device implementation, such as for UE  4000  of  FIG. 1 , computer device  20  may include packet validation component  4002  and concatenating component  4008 , such as in specially programmed computer readable instructions or code, firmware, hardware, or some combination thereof. 
     Referring to  FIG. 3 , an example methodology  3  for reducing round trip time for TCP packets in a wireless system is illustrated. While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and/or concurrently with other acts from that shown and described herein. For example, it is to be appreciated that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a methodology in accordance with one or more embodiments. 
     In an aspect, at block  30 , a RNC may receive a TCP packet from a server. The TCP may include a destination device, such as a user equipment (UE) in a wireless environment. In addition, at block  31 , the RNC may reform the received TCP packet into a set of RLC packets. In an aspect, the RNC may establish and utilize a TCP-RLC layer correlation instance by which TCP packet information it passed to the RLC layer for subsequent transmission to a UE and processing. In a further aspect, the RNC may transmit the set of RLC packets to a base station at block  32 . Once the RLC packets have been transmitted by the RNC, the RNC may send an accelerated TCP acknowledgement message to the server at block  33 . By sending the accelerated TCP acknowledgement to the server prior to receiving an acknowledgement for those RLC packets sent to the UE, the RNC may decrease round trip time for the TCP packet sent from the server and may correspondingly accelerate operation of the slow-start process in a wireless system. 
     For example, the RNC may send the accelerated TCP acknowledgement message with a previously-determined window size parameter. For instance, in one aspect, the RNC may intercept a TCP connection establishment phase and store an initial UE advertised window size parameter. For example, the RNC may be configured to sniff TCP packets within the RNC and identify the initial UE advertised window size parameter during the three way hand-shake phase of the TCP connection establishment. As such, in this case, the initial UE advertised window size parameter comprises the previously-determined window size parameter, such that the RNC sending the accelerated TCP acknowledgement message further comprises sending with the initial UE advertised window size. In another example, the RNC may receive an acknowledgement message corresponding to a prior TCP packet sent to the UE, wherein the acknowledgement message includes a window size parameter. In this case, the window size parameter from the acknowledgement message corresponding to the prior TCP packet comprises the previously-determined window size parameter. As such, the RNC sending the accelerated TCP acknowledgement message further comprises sending with the window size parameter from the acknowledgement message corresponding to the prior TCP packet. 
     Further, optional aspects of the present disclosure are represented in  FIG. 3  by dashed block perimeter lines. For example, at block  34 , the RNC may save the TCP packet in memory at block  34 , which may be implemented in the case the retransmission of the TCP packet and/or one or more RLC packets must be retransmitted. Additionally, at block  35 , the RNC may receive a UE ACK corresponding to the TCP packet composed of the concatenated RLC packets at the UE. This UE ACK may include one or more of a window size parameter, TCP packet acknowledgement information, and optionally uplink data. For example, the window size parameter may be a current advertised window size supported by UE  4000 . Further, for example, the TCP acknowledgement information may include, but is not limited to, an acknowledgement sequence number, for example, corresponding to a particular set of RLC packets  2012  that have been received. Also, for example, the uplink data may be actual data bytes (as opposed to information that would be in a header) including, but not limited to, a request for a webpage, TCP data bytes sent in the uplink, and other such type of data. As a result of receiving this UE ACK, in an aspect, the RNC may discard the TCP packet from the RNC memory at block  36 , as the RNC is aware that the UE has correctly received the TCP data and retransmission is likely unnecessary. 
     Furthermore, unlike legacy RNC procedures, which would forward this UE ACK to the server at upon receipt of the UE ACK message from the UE, the RNC of the present disclosure has previously sent the accelerated TCP ACK message to the server at block  33 . Therefore, the TCP packet acknowledgement data, which may indicate that the TCP packet has been correctly received at the UE, is not needed. Thus, in an aspect, the RNC may discard the TCP packet acknowledgement data at block  37 . In a further aspect, at block  38 , the RNC may extract and store the window size parameter from the received UE ACK message. Additionally, at block  39 , the RNC may add the window size parameter to the next accelerated TCP acknowledgement message sent to the server. As such, the server will have an approximate window size parameter to include in its next TCP packet transmission to the RNC. In an additional aspect, at blocks  41  and  43 , in a case where the UE ACK message includes uplink data, the RNC may extract the uplink data and then transmit the uplink data to the server, such as in a TCP message. 
     Referring to  FIG. 4 , in an additional optional aspect of the present disclosure, method  3  may continue from block  35  in  FIG. 3  to operate in a retransmit mode. For example, in some cases, at block  45 , the RNC may receive multiple UE acknowledgement messages from the UE corresponding to the same TCP packet, or the RNC may determine there is an RLC reset, e.g., based upon an RLC layer of RNC reaching a maximum number of retransmissions of one or more of the set of RLC packets. Accordingly, at block  47 , the RNC may determine to retransmit the corresponding TCP packet data to the UE. As such, at block  49 , the RNC may read the saved version of the corresponding TCP packet from the RNC memory. From this read TCP packet, at block  51 , the RNC may reform the TCP packet read from the memory into a new set of RLC packets. Further, at block  53 , the RNC may transmit this new set of RLC packets to the base station, which may in turn forward the set of RLC packets to the destination UE. At this point, the method may return to block  35  of  FIG. 3 , or to block  45  of  FIG. 4 , depending on what acknowledgements are subsequently received. 
     Referring to  FIG. 5 , in a use case that should not be construed as limiting, a message flow  55  represents one aspect of an operation of the present apparatus and methods. Message flow  55  assumes that the RLC reset procedure is selected by the RRC layer of RNC  2000 . For purposes of background, it is noted that the RLC layer of RNC  2000 , in WCDMA, is designed to retransmit the packets until a configured max number of transmissions (MAXDAT) is reached. If the packet cannot be delivered after (MAXDAT-1) transmissions then either the corresponding packet is discarded or the RLC layer is reset, e.g., to re-attempt delivery of the packet. If the RLC layer reset is selected, then the TCP acknowledgement is in a way redundant. As such, according to the present aspects, the RNC layer of RNC  2000  can assume that the packet will be successfully delivered, and send a fake TCP acknowledgement to the server  1000 . As such, the following message flow  55  describes an aspect of the present apparatus and methods. Also, please note that message flow  55  assumes that the TCP connection is established prior to step  1 . 
     At step  1 , the server  1000  is sending a TCP packet with sequence number 1. In an aspect, the amount of data received at the RNC  2000  from the server  1000  in each TCP packet is 1500 bytes, with the first such TCP packet containing a sequence number of 1. This packet gets to RNC  2000  and is broken up into 2 RLC PDUs with sequence numbers 100 and 101. At steps  2  and  3 , both these RLC PDUs are forwarded to the nodeB (which is not shown in this diagram for simplicity), which in turn sends them to the UE  4000 . Further, according to the present apparatus and methods, at step  4 , as soon as the TCP packet is chopped up into RLC packets and sent to the nodeB, the accelerated TCP acknowledgement is sent to the server  1000 . In this case, as noted herein, RNC  2000  may have previously monitored the connection establishment messages from UE  4000  to server  1000  and intercepted or otherwise acquired an initial window size parameter, e.g. “win: w”, of UE  4000  to use in this initial accelerated TCP acknowledgement sent in step  4 . Moreover, the accelerated TCP acknowledgement at step  4  may include TCP acknowledgement information, such as an acknowledgement sequence number, e.g., “ack#1501” in this case. For example, in an aspect, the present apparatus and methods determined the acknowledgement sequence number for the accelerated TCP acknowledgement according to the equation: sequence number (x)+data length; so, in the case of the first TCP packet, e.g. sequence #1, having a data length of 1500 bytes, the acknowledgement sequence number is “1501.” 
     In any case, this enhanced method of transmitting accelerated TCP acknowledgement removes all the time variations associated with multiple retransmissions of the RLC PDUs at the MAC level and at the RLC level. This method also reduces the RTT quite a bit and removes or reduces big fluctuations in the RTT. The RTT in this case as perceived by the server  1000  is made up of two components: Time taken from server  1000  to the RNC  2000  and time taken from RNC  2000  to the UE  4000 . With the present apparatus and methods, the time taken from RNC  2000  to the UE  4000  is removed from the equation. Further, for example, if the transmit queue of RNC  2000  is congested, then it might take RNC  2000  longer to split the TCP packet into multiple RLC packets. This is reflected in this enhanced method, as the TCP acknowledgement is sent after the RLC packets are sent out from RNC  2000  to the nodeB. 
     In this example, referring to steps  3  and  7 , RLC PDU with sequence number 101 goes through a re-transmission, with step  3  representing a transmission not received by UE  4000  and step  6  being the corresponding RLC-NACK. 
     In the meantime, at step  5 , server  1000  transmits the next TCP packet, e.g. having sequence number 1501 (which represents the next byte of data following the initial 1500 byte packet of data). As such, the present aspects have expedited the transmission of the next TCP packet from the server  1000  by sending out the accelerated TCP acknowledgement after the initial TCP packet was broken up into the two RLC packets and transmitted to the UE  4000  at steps  2  and  3 . Accordingly, the RNC  2000  breaks up the next TCP packet, e.g. sequence number 1501, into 2 RLC PDUs with sequence numbers 102 and 103. At steps  8  and  11 , both these RLC PDUs are forwarded to the nodeB (not shown), which in turn sends them to the UE  4000 . 
     At step  9 , once both the RLC PDUs that make the TCP packet with sequence number 1 are received by the UE  4000 , the UE  4000  sends an RLC acknowledgement, e.g. “RLC-ACK (101),” to RNC  2000 . Further, the UE  4000  forwards the packet to the socket layer on the UE. At step  10 , the socket layer of UE  4000  sends a TCP acknowledgement to the RNC  2000 , which in this aspect may include the acknowledgement sequence number, e.g. “ack#1501,” and the current advertised window parameter, e.g. “win: w1.” Optionally, in another aspect, at step  10 A, the TCP acknowledgement may additionally include uplink data. In either case, the RNC  2000  updates and stores the TCP acknowledgement sequence number, e.g., “ack#3001,” and extracts and stores the current advertised window parameter, e.g. “win: w1,” for use in the next accelerated acknowledgement, e.g., referring to the accelerated acknowledgement sent in step  12  after the last RLC PDU of TCP packet seq#1501 is transmitted to UE  4000  in step  11 . 
     Specifically, at step  12 , in the aspect of the TCP acknowledgement without uplink data, the RNC  2000  forwards the TCP acknowledgement with acknowledgement sequence number “ack#3001” and the current advertised window parameter “win: w1” to the server  1000 . 
     At optional step  12 A, which corresponds to optional step  10 A, the RNC  2000  forwards the TCP acknowledgement with acknowledgement sequence number “ack#3001,” the current advertised window parameter “win: w1,” and the uplink data to the server  1000 . 
     At step  13 , once both the RLC PDUs (e.g., 102 and 103) that make the TCP packet with sequence number 1501 are received by the UE  4000 , the UE  4000  sends an RLC acknowledgement, e.g. “RLC-ACK (101),” to RNC  2000 . Further, the UE  4000  forwards the packet to the socket layer on the UE. At step  14 , the socket layer of UE  4000  sends a TCP acknowledgement to the RNC  2000 , which in this aspect may include the acknowledgement sequence number, e.g. “ack#3001,” and the current advertised window parameter, e.g. “win: w2.” Although not illustrated, the RNC  2000  may extract and update the acknowledgement sequence number, and extract and save the current advertised window parameter, e.g. “win: w2.” 
     In this example, the TCP packet with sequence number 1501 does not go through retransmissions, and, as such, gets a TCP acknowledgement (e.g., at step  12  or step  12 A) sooner than the TCP packet with sequence number 1. 
     It should be noted that there may be H-ARQ level re-transmissions at the nodeB. These are not shown in the  FIG. 5 . For example, in an aspect, some MAC-ehs packets can go through in one attempt and some can take several retransmissions. When the MAC-ehs retransmissions, the MAC-e retransmissions in the uplink where the TCP acknowledgement is sent, and the RLC retransmissions are taken into account, there is quite a bit of variation in the TCP RTT as perceived by the server  1000  when the present apparatus and methods are not implemented. This variation not only makes it longer for TCP to go through the slow-start process, but also increases the Retransmission Timeout (RTO) value. The RTO is how long the server waits for an acknowledgement before retransmitting a packet. With a larger RTO, the user experience further deteriorates when there is a packet outage. As such, the present apparatus and methods provide an enhanced method by generating the accelerated TCP acknowledgement, as described herein, thereby avoiding the above-noted RTT and RTO issues related to H-ARQ level re-transmissions at the nodeB. 
     One might ask, what would happen if the RLC packets that make up a TCP packet are successfully delivered to the UE, but then dropped between the WCDMA protocol stack on the UE and the IP stack. In this case, the TCP ACK would have already been sent to the server and as a result the TCP stack at the server would have flushed the packets. Since RLC is successfully delivered, the RLC layer would have flushed these packets. The present apparatus and methods are configured to recover these packets by maintaining a queue, e.g., memory  2014 , to keep all the TCP packets, e.g., previous TCP packets  2018 , at the RNC  2000 . All incoming TCP packets are enqueued in this queue. Whenever a TCP ACK is received from the UE  4000 , the corresponding TCP packet is removed from this queue. If three or more consecutive TCP acknowledgements are received from the UE  4000 , then this is a signal to the RNC  2000  that the corresponding TCP packet is not received by the UE  4000 . In response, the RNC  2000  re-segments the TCP packet into multiple RLC packets and sends all of them. Since there is duplicate detection at the TCP layer at the UE  4000 , the UE  4000  should be able to drop redundant packets. As such, the UE  4000  should be able to build the original TCP packet from packets that were received before in combination with the newly received packets and construct a TCP packet out of them. 
     Referring to  FIG. 6 , an example system  6  is displayed for optimized Fast Dormancy in UMTS. For example, system  4  can reside at least partially within one or more network entities. It is to be appreciated that system  6  is represented as including functional blocks, which can be functional blocks that represent functions implemented by a processor, software, or combination thereof (e.g., firmware). System  5  includes a logical grouping  60  of electrical components that can act in conjunction. For instance, logical grouping  60  can include an electrical component  62  for receiving a TCP packet from a server. In an aspect, electrical component  62  may comprise communications component  23 . In an additional aspect, logical grouping  60  can include an electrical component  64  for reforming the TCP packet into a set of RLC packets. In an aspect, electrical component  64  may comprise TCP packet reforming component  2008  ( FIG. 1 ). In a further aspect, logical grouping  60  can include an electrical component  66  for transmitting the set of RLC packets to a base station. In an aspect, electrical component  66  may comprise communications component  23  ( FIG. 2 ). In a further aspect, logical grouping  60  can include an electrical component  68  for sending an accelerated TCP acknowledgement message to the server. In an aspect, electrical component  68  may comprise accelerated TCP ACK component  2004  ( FIG. 1 ). 
     Additionally, system  6  can include a memory  69  that retains instructions for executing functions associated with the electrical components  62 ,  64 ,  66 , and  68 , stores data used or obtained by the electrical components  62 ,  64 ,  66 , and  68 , etc. While shown as being external to memory  69 , it is to be understood that one or more of the electrical components  62 ,  64 ,  66 , and  68  can exist within memory  69 . In one example, electrical components  62 ,  64 ,  66 , and  68  can comprise at least one processor, or each electrical component  62 ,  64 ,  66 , and  68  can be a corresponding module of at least one processor. Moreover, in an additional or alternative example, electrical components  62 ,  64 ,  66 , and  68  can be a computer program product including a computer readable medium, where each electrical component  62 ,  64 ,  66 , and  68  can be corresponding code. 
       FIG. 7  is a block diagram illustrating an example of a hardware implementation for an apparatus  100  employing a processing system  114 . In an aspect, apparatus  100  may be RNC  2000  of  FIG. 1  and may be capable of transmitting accelerated TCP packet ACK messages to a server. In this example, the processing system  114  may be implemented with a bus architecture, represented generally by the bus  102 . The bus  102  may include any number of interconnecting buses and bridges depending on the specific application of the processing system  114  and the overall design constraints. The bus  102  links together various circuits including one or more processors, represented generally by the processor  104 , and computer-readable media, represented generally by the computer-readable medium  106 . The bus  102  may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. A bus interface  108  provides an interface between the bus  102  and a transceiver  110 . The transceiver  110  provides a means for communicating with various other apparatus over a transmission medium. Depending upon the nature of the apparatus, a user interface  112  (e.g., keypad, display, speaker, microphone, joystick) may also be provided. 
     The processor  104  is responsible for managing the bus  102  and general processing, including the execution of software stored on the computer-readable medium  106 . The software, when executed by the processor  104 , causes the processing system  114  to perform the various functions described infra for any particular apparatus. The computer-readable medium  106  may also be used for storing data that is manipulated by the processor  104  when executing software. 
     The various concepts presented throughout this disclosure may be implemented across a broad variety of telecommunication systems, network architectures, and communication standards. By way of example and without limitation, the aspects of the present disclosure illustrated in  FIG. 8  are presented with reference to a UMTS system  200  employing a W-CDMA air interface. A UMTS network includes three interacting domains: a Core Network (CN)  204 , a UMTS Terrestrial Radio Access Network (UTRAN)  202 , and User Equipment (UE)  210 . In an aspect, UE  210  may correspond to UE  4000  of  FIG. 1 . In this example, the UTRAN  202  provides various wireless services including telephony, video, data, messaging, broadcasts, and/or other services. The UTRAN  202  may include a plurality of Radio Network Subsystems (RNSs) such as an RNS  207 , each controlled by a respective Radio Network Controller (RNC) such as an RNC  206 . In an aspect, each RNC  206  may correspond to RNC  2000  of  FIG. 1 . Here, the UTRAN  202  may include any number of RNCs  206  and RNSs  207  in addition to the RNCs  206  and RNSs  207  illustrated herein. The RNC  206  is an apparatus responsible for, among other things, assigning, reconfiguring and releasing radio resources within the RNS  207 . The RNC  206  may be interconnected to other RNCs (not shown) in the UTRAN  202  through various types of interfaces such as a direct physical connection, a virtual network, or the like, using any suitable transport network. 
     Communication between a UE  210  and a Node B  208  may be considered as including a physical (PHY) layer and a medium access control (MAC) layer. Further, communication between a UE  210  and an RNC  206  by way of a respective Node B  208  may be considered as including a radio resource control (RRC) layer. In the instant specification, the PHY layer may be considered layer 1; the MAC layer may be considered layer 2; and the RRC layer may be considered layer 3. Information hereinbelow utilizes terminology introduced in the RRC Protocol Specification, 3GPP TS 25.331 v9.1.0, incorporated herein by reference. 
     The geographic region covered by the RNS  207  may be divided into a number of cells, with a radio transceiver apparatus serving each cell. A radio transceiver apparatus is commonly referred to as a Node B in UMTS applications, but may also be referred to by those skilled in the art as a base station (BS), a base transceiver station (BTS), a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), an access point (AP), or some other suitable terminology. For clarity, three Node Bs  208  are shown in each RNS  207 ; however, the RNSs  207  may include any number of wireless Node Bs. The Node Bs  208  provide wireless access points to a CN  204  for any number of mobile apparatuses. Examples of a mobile apparatus include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a notebook, a netbook, a smartbook, a personal digital assistant (PDA), a satellite radio, a global positioning system (GPS) device, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, or any other similar functioning device. The mobile apparatus is commonly referred to as a UE in UMTS applications, but may also be referred to by those skilled in the art as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. In a UMTS system, the UE  210  may further include a universal subscriber identity module (USIM)  211 , which contains a user&#39;s subscription information to a network. For illustrative purposes, one UE  210  is shown in communication with a number of the Node Bs  208 . The DL, also called the forward link, refers to the communication link from a Node B  208  to a UE  210 , and the UL, also called the reverse link, refers to the communication link from a UE  210  to a Node B  208 . 
     The CN  204  interfaces with one or more access networks, such as the UTRAN  202 . As shown, the CN  204  is a GSM core network. However, as those skilled in the art will recognize, the various concepts presented throughout this disclosure may be implemented in a RAN, or other suitable access network, to provide UEs with access to types of CNs other than GSM networks. 
     The CN  204  includes a circuit-switched (CS) domain and a packet-switched (PS) domain. Some of the circuit-switched elements are a Mobile services Switching Centre (MSC), a Visitor location register (VLR) and a Gateway MSC. Packet-switched elements include a Serving GPRS Support Node (SGSN) and a Gateway GPRS Support Node (GGSN). Some network elements, like EIR, HLR, VLR and AuC may be shared by both of the circuit-switched and packet-switched domains. In the illustrated example, the CN  204  supports circuit-switched services with a MSC  212  and a GMSC  214 . In some applications, the GMSC  214  may be referred to as a media gateway (MGW). One or more RNCs, such as the RNC  206 , may be connected to the MSC  212 . The MSC  212  is an apparatus that controls call setup, call routing, and UE mobility functions. The MSC  212  also includes a VLR that contains subscriber-related information for the duration that a UE is in the coverage area of the MSC  212 . The GMSC  214  provides a gateway through the MSC  212  for the UE to access a circuit-switched network  216 . The GMSC  214  includes a home location register (HLR)  215  containing subscriber data, such as the data reflecting the details of the services to which a particular user has subscribed. The HLR is also associated with an authentication center (AuC) that contains subscriber-specific authentication data. When a call is received for a particular UE, the GMSC  214  queries the HLR  215  to determine the UE&#39;s location and forwards the call to the particular MSC serving that location. 
     The CN  204  also supports packet-data services with a serving GPRS support node (SGSN)  218  and a gateway GPRS support node (GGSN)  220 . GPRS, which stands for General Packet Radio Service, is designed to provide packet-data services at speeds higher than those available with standard circuit-switched data services. The GGSN  220  provides a connection for the UTRAN  202  to a packet-based network  222 . The packet-based network  222  may be the Internet, a private data network, or some other suitable packet-based network. The primary function of the GGSN  220  is to provide the UEs  210  with packet-based network connectivity. Data packets may be transferred between the GGSN  220  and the UEs  210  through the SGSN  218 , which performs primarily the same functions in the packet-based domain as the MSC  212  performs in the circuit-switched domain. 
     An air interface for UMTS may utilize a spread spectrum Direct-Sequence Code Division Multiple Access (DS-CDMA) system. The spread spectrum DS-CDMA spreads user data through multiplication by a sequence of pseudorandom bits called chips. The “wideband” W-CDMA air interface for UMTS is based on such direct sequence spread spectrum technology and additionally calls for a frequency division duplexing (FDD). FDD uses a different carrier frequency for the UL and DL between a Node B  208  and a UE  210 . Another air interface for UMTS that utilizes DS-CDMA, and uses time division duplexing (TDD), is the TD-SCDMA air interface. Those skilled in the art will recognize that although various examples described herein may refer to a W-CDMA air interface, the underlying principles may be equally applicable to a TD-SCDMA air interface. 
     An HSPA air interface includes a series of enhancements to the 3G/W-CDMA air interface, facilitating greater throughput and reduced latency. Among other modifications over prior releases, HSPA utilizes hybrid automatic repeat request (HARQ), shared channel transmission, and adaptive modulation and coding. The standards that define HSPA include HSDPA (high speed downlink packet access) and HSUPA (high speed uplink packet access, also referred to as enhanced uplink, or EUL). 
     HSDPA utilizes as its transport channel the high-speed downlink shared channel (HS-DSCH). The HS-DSCH is implemented by three physical channels: the high-speed physical downlink shared channel (HS-PDSCH), the high-speed shared control channel (HS-SCCH), and the high-speed dedicated physical control channel (HS-DPCCH). 
     Among these physical channels, the HS-DPCCH carries the HARQ ACK/NACK signaling on the uplink to indicate whether a corresponding packet transmission was decoded successfully. That is, with respect to the downlink, the UE  210  provides feedback to the node B  208  over the HS-DPCCH to indicate whether it correctly decoded a packet on the downlink. 
     HS-DPCCH further includes feedback signaling from the UE  210  to assist the node B  208  in taking the right decision in terms of modulation and coding scheme and precoding weight selection, this feedback signaling including the CQI and PCI. “HSPA Evolved” or HSPA+ is an evolution of the HSPA standard that includes MIMO and 64-QAM, enabling increased throughput and higher performance. That is, in an aspect of the disclosure, the node B  208  and/or the UE  210  may have multiple antennas supporting MIMO technology. The use of MIMO technology enables the node B  208  to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. 
     Multiple Input Multiple Output (MIMO) is a term generally used to refer to multi-antenna technology, that is, multiple transmit antennas (multiple inputs to the channel) and multiple receive antennas (multiple outputs from the channel). MIMO systems generally enhance data transmission performance, enabling diversity gains to reduce multipath fading and increase transmission quality, and spatial multiplexing gains to increase data throughput. 
     Spatial multiplexing may be used to transmit different streams of data simultaneously on the same frequency. The data steams may be transmitted to a single UE  210  to increase the data rate or to multiple UEs  210  to increase the overall system capacity. This is achieved by spatially precoding each data stream and then transmitting each spatially precoded stream through a different transmit antenna on the downlink. The spatially precoded data streams arrive at the UE(s)  210  with different spatial signatures, which enables each of the UE(s)  210  to recover the one or more the data streams destined for that UE  210 . On the uplink, each UE  210  may transmit one or more spatially precoded data streams, which enables the node B  208  to identify the source of each spatially precoded data stream. 
     Spatial multiplexing may be used when channel conditions are good. When channel conditions are less favorable, beamforming may be used to focus the transmission energy in one or more directions, or to improve transmission based on characteristics of the channel. This may be achieved by spatially precoding a data stream for transmission through multiple antennas. To achieve good coverage at the edges of the cell, a single stream beamforming transmission may be used in combination with transmit diversity. 
     Generally, for MIMO systems utilizing n transmit antennas, n transport blocks may be transmitted simultaneously over the same carrier utilizing the same channelization code. Note that the different transport blocks sent over the n transmit antennas may have the same or different modulation and coding schemes from one another. On the other hand, Single Input Multiple Output (SIMO) generally refers to a system utilizing a single transmit antenna (a single input to the channel) and multiple receive antennas (multiple outputs from the channel). Thus, in a SIMO system, a single transport block is sent over the respective carrier. 
     Referring to  FIG. 9 , an access network  300  in a UTRAN architecture is illustrated, which may allow for utilization of accelerated TCP ACK message transmission to reduce round trip time for TCP packets. The multiple access wireless communication system includes multiple cellular regions (cells), including cells  302 ,  304 , and  306 , each of which may include one or more sectors. The multiple sectors can be formed by groups of antennas with each antenna responsible for communication with UEs in a portion of the cell. For example, in cell  302 , antenna groups  312 ,  314 , and  316  may each correspond to a different sector. In cell  304 , antenna groups  318 ,  320 , and  322  each correspond to a different sector. In cell  306 , antenna groups  324 ,  326 , and  328  each correspond to a different sector. The cells  302 ,  304  and  306  may include several wireless communication devices, e.g., User Equipment or UEs, which may be in communication with one or more sectors of each cell  302 ,  304  or  306 , and may correspond to UE  4000 . For example, UEs  330  and  332  may be in communication with Node B  342 , UEs  334  and  336  may be in communication with Node B  344 , and UEs  338  and  340  can be in communication with Node B  346 . Here, each Node B  342 ,  344 ,  346  is configured to provide an access point to a CN  204  (see  FIG. 8 ) for all the UEs  330 ,  332 ,  334 ,  336 ,  338 ,  340  in the respective cells  302 ,  304 , and  306 . 
     As the UE  334  moves from the illustrated location in cell  304  into cell  306 , a serving cell change (SCC) or handover may occur in which communication with the UE  334  transitions from the cell  304 , which may be referred to as the source cell, to cell  306 , which may be referred to as the target cell. Management of the handover procedure may take place at the UE  334 , at the Node Bs corresponding to the respective cells, at a radio network controller  206  (see  FIG. 8 ), or at another suitable node in the wireless network. For example, during a call with the source cell  304 , or at any other time, the UE  334  may monitor various parameters of the source cell  304  as well as various parameters of neighboring cells such as cells  306  and  302 . Further, depending on the quality of these parameters, the UE  334  may maintain communication with one or more of the neighboring cells. During this time, the UE  334  may maintain an Active Set, that is, a list of cells that the UE  334  is simultaneously connected to (i.e., the UTRA cells that are currently assigning a downlink dedicated physical channel DPCH or fractional downlink dedicated physical channel F-DPCH to the UE  334  may constitute the Active Set). 
     The modulation and multiple access scheme employed by the access network  300  may vary depending on the particular telecommunications standard being deployed. By way of example, the standard may include Evolution-Data Optimized (EV-DO) or Ultra Mobile Broadband (UMB). EV-DO and UMB are air interface standards promulgated by the 3rd Generation Partnership Project 2 (3GPP2) as part of the CDMA2000 family of standards and employs CDMA to provide broadband Internet access to mobile stations. The standard may alternately be Universal Terrestrial Radio Access (UTRA) employing Wideband-CDMA (W-CDMA) and other variants of CDMA, such as TD-SCDMA; Global System for Mobile Communications (GSM) employing TDMA; and Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDM employing OFDMA. UTRA, E-UTRA, UMTS, LTE, LTE Advanced, and GSM are described in documents from the 3GPP organization. CDMA2000 and UMB are described in documents from the 3GPP2 organization. The actual wireless communication standard and the multiple access technology employed will depend on the specific application and the overall design constraints imposed on the system. 
     The radio protocol architecture may take on various forms depending on the particular application. An example for an HSPA system will now be presented with reference to  FIG. 10 . 
     Referring to  FIG. 10 , an example radio protocol architecture  400  relates to the user plane  402  and the control plane  404  of a user equipment (UE) or node B/base station. For example, architecture  400  may be included in a UE such as UE  4000  ( FIG. 1 ). The radio protocol architecture  400  for the UE and node B is shown with three layers: Layer 1  406 , Layer 2  408 , and Layer 3  410 . Layer 1  406  is the lowest lower and implements various physical layer signal processing functions. As such, Layer 1  406  includes the physical layer  407 . Layer 2 (L2 layer)  408  is above the physical layer  407  and is responsible for the link between the UE and node B over the physical layer  407 . Layer 3 (L3 layer)  410  includes a radio resource control (RRC) sublayer  415 . The RRC sublayer  415  handles the control plane signaling of Layer 3 between the UE and the UTRAN. 
     In the user plane, the L2 layer  408  includes a media access control (MAC) sublayer  409 , a radio link control (RLC) sublayer  411 , and a packet data convergence protocol (PDCP)  413  sublayer, which are terminated at the node B on the network side. Although not shown, the UE may have several upper layers above the L2 layer  408  including a network layer (e.g., IP layer) that is terminated at a PDN gateway on the network side, and an application layer that is terminated at the other end of the connection (e.g., far end UE, server, etc.). 
     The PDCP sublayer  413  provides multiplexing between different radio bearers and logical channels. The PDCP sublayer  413  also provides header compression for upper layer data packets to reduce radio transmission overhead, security by ciphering the data packets, and handover support for UEs between node Bs. The RLC sublayer  411  provides segmentation and reassembly of upper layer data packets, retransmission of lost data packets, and reordering of data packets to compensate for out-of-order reception due to hybrid automatic repeat request (HARQ). The MAC sublayer  409  provides multiplexing between logical and transport channels. The MAC sublayer  409  is also responsible for allocating the various radio resources (e.g., resource blocks) in one cell among the UEs. The MAC sublayer  409  is also responsible for HARQ operations. 
       FIG. 11  is a block diagram of a Node B  510  in communication with a UE  550 , where the Node B  510  may be the base station  3000  in  FIG. 1 , and the UE  550  may be the UE  4000  in  FIG. 1 . In the downlink communication, a transmit processor  520  may receive data from a data source  512  and control signals from a controller/processor  540 . The transmit processor  520  provides various signal processing functions for the data and control signals, as well as reference signals (e.g., pilot signals). For example, the transmit processor  520  may provide cyclic redundancy check (CRC) codes for error detection, coding and interleaving to facilitate forward error correction (FEC), mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM), and the like), spreading with orthogonal variable spreading factors (OVSF), and multiplying with scrambling codes to produce a series of symbols. Channel estimates from a channel processor  544  may be used by a controller/processor  540  to determine the coding, modulation, spreading, and/or scrambling schemes for the transmit processor  520 . These channel estimates may be derived from a reference signal transmitted by the UE  550  or from feedback from the UE  550 . The symbols generated by the transmit processor  520  are provided to a transmit frame processor  530  to create a frame structure. The transmit frame processor  530  creates this frame structure by multiplexing the symbols with information from the controller/processor  540 , resulting in a series of frames. The frames are then provided to a transmitter  532 , which provides various signal conditioning functions including amplifying, filtering, and modulating the frames onto a carrier for downlink transmission over the wireless medium through antenna  534 . The antenna  534  may include one or more antennas, for example, including beam steering bidirectional adaptive antenna arrays or other similar beam technologies. 
     At the UE  550 , a receiver  554  receives the downlink transmission through an antenna  552  and processes the transmission to recover the information modulated onto the carrier. The information recovered by the receiver  554  is provided to a receive frame processor  560 , which parses each frame, and provides information from the frames to a channel processor  594  and the data, control, and reference signals to a receive processor  570 . The receive processor  570  then performs the inverse of the processing performed by the transmit processor  520  in the Node B  510 . More specifically, the receive processor  570  descrambles and despreads the symbols, and then determines the most likely signal constellation points transmitted by the Node B  510  based on the modulation scheme. These soft decisions may be based on channel estimates computed by the channel processor  594 . The soft decisions are then decoded and deinterleaved to recover the data, control, and reference signals. The CRC codes are then checked to determine whether the frames were successfully decoded. The data carried by the successfully decoded frames will then be provided to a data sink  572 , which represents applications running in the UE  550  and/or various user interfaces (e.g., display). Control signals carried by successfully decoded frames will be provided to a controller/processor  590 . When frames are unsuccessfully decoded by the receiver processor  570 , the controller/processor  590  may also use an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support retransmission requests for those frames. 
     In the uplink, data from a data source  578  and control signals from the controller/processor  590  are provided to a transmit processor  580 . The data source  578  may represent applications running in the UE  550  and various user interfaces (e.g., keyboard). Similar to the functionality described in connection with the downlink transmission by the Node B  510 , the transmit processor  580  provides various signal processing functions including CRC codes, coding and interleaving to facilitate FEC, mapping to signal constellations, spreading with OVSFs, and scrambling to produce a series of symbols. Channel estimates, derived by the channel processor  594  from a reference signal transmitted by the Node B  510  or from feedback contained in the midamble transmitted by the Node B  510 , may be used to select the appropriate coding, modulation, spreading, and/or scrambling schemes. The symbols produced by the transmit processor  580  will be provided to a transmit frame processor  582  to create a frame structure. The transmit frame processor  582  creates this frame structure by multiplexing the symbols with information from the controller/processor  590 , resulting in a series of frames. The frames are then provided to a transmitter  556 , which provides various signal conditioning functions including amplification, filtering, and modulating the frames onto a carrier for uplink transmission over the wireless medium through the antenna  552 . 
     The uplink transmission is processed at the Node B  510  in a manner similar to that described in connection with the receiver function at the UE  550 . A receiver  535  receives the uplink transmission through the antenna  534  and processes the transmission to recover the information modulated onto the carrier. The information recovered by the receiver  535  is provided to a receive frame processor  536 , which parses each frame, and provides information from the frames to the channel processor  544  and the data, control, and reference signals to a receive processor  538 . The receive processor  538  performs the inverse of the processing performed by the transmit processor  580  in the UE  550 . The data and control signals carried by the successfully decoded frames may then be provided to a data sink  539  and the controller/processor, respectively. If some of the frames were unsuccessfully decoded by the receive processor, the controller/processor  540  may also use an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support retransmission requests for those frames. 
     The controller/processors  540  and  590  may be used to direct the operation at the Node B  510  and the UE  550 , respectively. For example, the controller/processors  540  and  590  may provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. The computer readable media of memories  542  and  592  may store data and software for the Node B  510  and the UE  550 , respectively. A scheduler/processor  546  at the Node B  510  may be used to allocate resources to the UEs and schedule downlink and/or uplink transmissions for the UEs. 
     Several aspects of a telecommunications system have been presented with reference to a W-CDMA system. As those skilled in the art will readily appreciate, various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures and communication standards. 
     By way of example, various aspects may be extended to other UMTS systems such as TD-SCDMA, High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), High Speed Packet Access Plus (HSPA+) and TD-CDMA. Various aspects may also be extended to systems employing Long Term Evolution (LTE) (in FDD, TDD, or both modes), LTE-Advanced (LTE-A) (in FDD, TDD, or both modes), CDMA2000, Evolution-Data Optimized (EV-DO), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-Wideband (UWB), Bluetooth, and/or other suitable systems. The actual telecommunication standard, network architecture, and/or communication standard employed will depend on the specific application and the overall design constraints imposed on the system. 
     In accordance with various aspects of the disclosure, an element, or any portion of an element, or any combination of elements may be implemented with a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside on a computer-readable medium. The computer-readable medium may be a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip), an optical disk (e.g., compact disk (CD), digital versatile disk (DVD)), a smart card, a flash memory device (e.g., card, stick, key drive), random access memory (RAM), read only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium may also include, by way of example, a carrier wave, a transmission line, and any other suitable medium for transmitting software and/or instructions that may be accessed and read by a computer. The computer-readable medium may be resident in the processing system, external to the processing system, or distributed across multiple entities including the processing system. The computer-readable medium may be embodied in a computer-program product. By way of example, a computer-program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system. 
     It is to be understood that the specific order or hierarchy of steps in the methods disclosed is an illustration of exemplary processes. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented unless specifically recited therein. 
     The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the term “some” refers to one or more. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, b and c. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”