Method and apparatus for media access control -based fast cell switching for high-speed packet access

Abstract

Methods and apparatuses for facilitating switching HSPA (high speed packet access) serving cells from each of an RNC (radio network controller), base station, and access terminal are provided. The RNC pre-configures an access terminal and each base station in an active set for HS-DSCH operation by providing identification codes identifying each of the base stations. The RNC transmits data packets tagged with sequence numbers to each base station where they are synchronously buffered. The access terminal initiates a handover by transmitting a PDU (protocol data unit) to each of the base stations. The PDU is encoded with the identification code of a target base station and a sequence number of a subsequent packet. The target receives the PDU and directly completes the handover with the access terminal.

1 . A method for a base station in a wireless network to facilitate switching HSPA (high speed packet access) serving cells, comprising:
 employing a processor to execute computer executable instructions stored on a computer readable storage medium to implement the following acts:
 receiving configuration data from an RNC (radio network controller), the configuration data including an identification code assigned to the base station; 
 buffering a sequence of data packets received from the RNC into a buffer, each of the data packets including a sequence number; 
 monitoring each of a series of PDUs (protocol data units) received from an access terminal, each of the PDUs encoded with a particular identification code and a particular sequence number; and 
 transmitting the data packets to the access terminal as a function of the identification code and sequence number encoded in each PDU. 
   
   
   
       2 . The method of  claim 1 , the transmitting act further comprising transmitting the data packets as a function of receiving an acknowledge-correct/acknowledge-error (ACK/NACK) signal from the access terminal. 
   
   
       3 . The method of  claim 2 , the transmitting act further comprising transmitting the data packets so long as an ACK/NACK signal is received. 
   
   
       4 . The method of  claim 2  comprising making a determination that a series of ACK/NACK signals is no longer being received, the transmitting act further comprising ceasing to transmit the data packets a threshold amount of time after the determination is made. 
   
   
       5 . The method of  claim 1  further comprising transmitting a notification to the RNC indicating that the base station has begun transmitting data packets to the access terminal. 
   
   
       6 . The method of  claim 1 , the configuration data including instructions for discarding data packets from the buffer as a function of the sequence number encoded in a received PDU. 
   
   
       7 . A base station for facilitating switching HSPA (high speed packet access) serving cells within a wireless environment, comprising:
 a memory component configured to store computer-readable instructions;   a processing component coupled to the memory component and configured to execute the computer-readable instructions, the instructions including instructions for implementing a plurality of acts on the following components:
 a receiving component configured to receive configuration data and data packets from an RNC (radio network controller), wherein the configuration data includes an identification code assigned to the base station, and wherein each of the data packets includes a sequence number, the receiving component also configured to receive each of a series of PDUs (protocol data units) transmitted by an access terminal, wherein each of the PDUs is encoded with a particular identification code and a particular sequence number; 
 a buffering component configured to sequentially buffer the data packets received from the RNC; and 
 a transmitting component configured to transmit the data packets to the access terminal as a function of the identification code and sequence number encoded in each PDU. 
   
   
   
       8 . The base station of  claim 7 , the receiving component further configured to receive an acknowledge-correct/acknowledge-error (ACK/NACK) signal from the access terminal, the transmitting component further configured to transmit the data packets as a function of receiving the ACK/NACK signal. 
   
   
       9 . The base station of  claim 8 , the transmitting component further configured to transmit the data packets so long as an ACK/NACK signal is received. 
   
   
       10 . The base station of  claim 8  further comprising a timing component, the timing component configured to make a determination that a threshold amount of time has elapsed since receiving an ACK/NACK signal, the transmitting component further configured to stop transmitting the data packets once the determination is made. 
   
   
       11 . The base station of  claim 7 , the transmitting component further configured to transmit a notification to the RNC indicating that the base station has begun transmitting data packets to the access terminal. 
   
   
       12 . The base station of  claim 7 , the buffering component further configured to discard data packets as a function of the sequence number encoded in a received PDU. 
   
   
       13 . A computer program product for facilitating switching HSPA (high speed packet access) serving cells from a base station, comprising:
 a computer-readable storage medium comprising:
 code for receiving configuration data from an RNC (radio network controller), the configuration data including an identification code assigned to the base station; 
 code for buffering a sequence of data packets received from the RNC into a buffer, each of the data packets including a sequence number; 
 code for monitoring each of a series of PDUs (protocol data units) received from an access terminal, each of the PDUs encoded with a particular identification code and a particular sequence number; and 
 code for transmitting the data packets to the access terminal as a function of the identification code and sequence number encoded in each PDU. 
   
   
   
       14 . An apparatus for facilitating switching HSPA (high speed packet access) serving cells from a base station, comprising:
 means for receiving configuration data from an RNC (radio network controller), the configuration data including an identification code assigned to the base station;   means for buffering a sequence of data packets received from the RNC into a buffer, each of the data packets including a sequence number;   means for monitoring each of a series of PDUs (protocol data units) received from an access terminal, each of the PDUs encoded with a particular identification code and a particular sequence number; and   means for transmitting the data packets to the access terminal as a function of the identification code and sequence number encoded in each PDU.   
   
   
       15 . A method for an access terminal in a wireless network to facilitate switching HSPA (high speed packet access) serving cells, comprising:
 employing a processor to execute computer executable instructions stored on a computer readable storage medium to implement the following acts:
 receiving configuration data, the configuration data including a set of identification codes, each of the identification codes assigned to one of a plurality of base stations in an active set; 
 receiving a first set of data packets sequentially from a source base station, the source base station included in the plurality of base stations, the first set of data packets being a subset of a series of data packets, wherein each of the series of data packets includes a sequence number; 
 selecting a target base station from the plurality of base stations as a function of a signal quality ascertained for each of the plurality of base stations; 
 transmitting a PDU (protocol data unit) to each of the plurality of base stations, the PDU encoded with an identification code corresponding to the target base station and a sequence number corresponding to a subsequent data packet; and 
 performing a handover as a function of whether a second set of data packets is received from the target base station, the second set of data packets being a subset of the series of data packets, wherein the second set of packets begins with the subsequent data packet. 
   
   
   
       16 . The method of  claim 15 , the selecting act comprising continuously sampling signals received from each of the plurality of base stations. 
   
   
       17 . The method of  claim 15 , the selecting act comprising periodically sampling signals received from each of the plurality of base stations. 
   
   
       18 . The method of  claim 15 , the selecting act comprising sampling signals received from each of the plurality of base stations according to instructions provided as part of the configuration data. 
   
   
       19 . The method of  claim 15 , the performing act comprising ascertaining whether a threshold amount of time has elapsed since the PDU has been transmitted, wherein the handover is cancelled if the subsequent packet is not received before the threshold amount of time has elapsed. 
   
   
       20 . The method of  claim 19 , the configuration data including instructions for determining the threshold amount of time. 
   
   
       21 . An access terminal for facilitating switching HSPA (high speed packet access) serving cells within a wireless environment, comprising:
 a memory component configured to store computer-readable instructions;   a processing component coupled to the memory component and configured to execute the computer-readable instructions, the instructions including instructions for implementing a plurality of acts on the following components:
 a receiving component configured to receive configuration data and a first set of data packets, wherein the configuration data includes a set of identification codes, each of the identification codes assigned to one of a plurality of base stations in an active set, and wherein the first set of data packets are sequentially received from a source base station, the source base station included in the plurality of base stations, the first set of data packets being a subset of a series of data packets in which each of the series of data packets includes a sequence number; 
 a signal monitoring component configured to ascertain a signal quality from each of the plurality of base stations and to select a target base station as a function of the ascertained signal qualities; 
 a PDU (protocol data unit) encoding component configured to encode a PDU with an identification code corresponding to the target base station and a sequence number corresponding to a subsequent data packet; and 
 a transmitting component configured to transmit the PDU to each of the plurality of base stations so as to initiate a handover process, the handover process completed as a function of whether a second set of data packets is received from the target base station, the second set of data packets being a subset of the series of data packets, wherein the second set of packets begins with the subsequent data packet. 
   
   
   
       22 . The access terminal of  claim 21 , the signal monitoring component configured to continuously sample signals received from each of the plurality of base stations. 
   
   
       23 . The access terminal of  claim 21 , the signal monitoring component configured to periodically sample signals received from each of the plurality of base stations. 
   
   
       24 . The access terminal of  claim 21 , the signal monitoring component configured to sample signals received from each of the plurality of base stations according to instructions provided as part of the configuration data. 
   
   
       25 . The access terminal of  claim 21  further comprising a timing component configured to ascertain whether a threshold amount of time has elapsed since the PDU has been transmitted, wherein the handover process is cancelled if the subsequent packet is not received before the threshold amount of time has elapsed. 
   
   
       26 . The access terminal of  claim 25 , the configuration data including instructions for determining the threshold amount of time. 
   
   
       27 . A computer program product for facilitating switching HSPA (high speed packet access) serving cells from an access terminal, comprising:
 a computer-readable storage medium comprising:
 code for receiving configuration data, the configuration data including a set of identification codes, each of the identification codes assigned to one of a plurality of base stations in an active set; 
 code for receiving a first set of data packets sequentially from a source base station, the source base station included in the plurality of base stations, the first set of data packets being a subset of a series of data packets, wherein each of the series of data packets includes a sequence number; 
 code for selecting a target base station from the plurality of base stations as a function of a signal quality ascertained for each of the plurality of base stations; 
 code for transmitting a PDU (protocol data unit) to each of the plurality of base stations, the PDU encoded with an identification code corresponding to the target base station and a sequence number corresponding to a subsequent data packet; and 
 code for performing a handover as a function of whether a second set of data packets is received from the target base station, the second set of data packets being a subset of the series of data packets, wherein the second set of packets begins with the subsequent data packet. 
   
   
   
       28 . An apparatus for facilitating switching HSPA (high speed packet access) serving cells from an access terminal, comprising:
 means for receiving configuration data, the configuration data including a set of identification codes, each of the identification codes assigned to one of a plurality of base stations in an active set;   means for receiving a first set of data packets sequentially from a source base station, the source base station included in the plurality of base stations, the first set of data packets being a subset of a series of data packets, wherein each of the series of data packets includes a sequence number;   means for selecting a target base station from the plurality of base stations as a function of a signal quality ascertained for each of the plurality of base stations;   means for transmitting a PDU (protocol data unit) to each of the plurality of base stations, the PDU encoded with an identification code corresponding to the target base station and a sequence number corresponding to a subsequent data packet; and   means for performing a handover as a function of whether a second set of data packets is received from the target base station, the second set of data packets being a subset of the series of data packets, wherein the second set of packets begins with the subsequent data packet.   
   
   
       29 . A method for an RNC (radio network controller) in a wireless network to facilitate switching HSPA (high speed packet access) serving cells, comprising:
 employing a processor to execute computer executable instructions stored on a computer readable storage medium to implement the following acts:
 identifying a plurality of base stations comprising an active set for an access terminal; 
 generating an identification code for each of the plurality of base stations; 
 pre-configuring the access terminal and the plurality of base stations, wherein the access terminal is provided with the identification code for each of the plurality of base stations, and wherein each of the plurality of base stations is respectively provided with its corresponding identification code; and 
 transmitting a sequence of data packets simultaneously to each of the plurality of base stations, each of the data packets including a sequence number. 
   
   
   
       30 . An RNC (radio network controller) for facilitating switching HSPA (high speed packet access) serving cells within a wireless environment, comprising:
 a memory component configured to store computer-readable instructions;   a processing component coupled to the memory component and configured to execute the computer-readable instructions, the instructions including instructions for implementing a plurality of acts on the following components:
 an identification code component configured to generate an identification code for each of a plurality of base stations, the plurality of base stations comprising an active set for an access terminal; 
 a configuration component configured to provide configuration data to the access terminal and the plurality of base stations, wherein the access terminal is provided with the identification code for each of the plurality of base stations, and wherein each of the plurality of base stations is respectively provided with its corresponding identification code; 
 a receiving component configured to receive a series of data packets from a core network; 
 a tagging component configured to tag each of the series of data packets with a sequence number, each of the sequence numbers corresponding to a desired order for receiving the data packet; and 
 a transmitting component configured to simultaneously transmit the series of data packets to each of the plurality of base stations sequentially according to the sequence number of each data packet.