Wireless communication terminal and wireless communication method

• US 8,054,852 B2
• Filed: 02/27/2007
• Issued: 11/08/2011
• Est. Priority Date: 02/28/2006
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Sugiyama, Takatoshi, Yamada, Akira, Igarashi, Kei
• Primary Examiner(s): Moe; Aung S
• Assistant Examiner(s): Louis; Vincelas
• Application Number:
  US11/679,382
• Publication Number:
  US 20070201505A1
• Time in Patent Office: 1,715 Days
• Field of Search: 370/338, 370/349, 370/432, 370/412, 370/445, 370/455, 370/503, 455/452, 455/574, 340/572.1, 463/1
• US Class Current: 370/445
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 92/10 between terminal device and access point, i.e. wireless air interface

Abstract

A communication terminal used in a mobile communication system complying with a carrier sense multiple access scheme is disclosed. The communication terminal includes: a receiving unit configured to receive a wireless packet transmitted by another communication terminal or a base station; a determination unit configured to determine periodic transmission timing of the communication terminal based on determination criterion information included in the wireless packet; and a transmission unit configured to periodically transmit wireless packets to the base station based on the transmission timing.

Claims

1. A communication terminal used in a mobile communication system complying with a carrier sense multiple access scheme and including a plurality of communication terminals that transmit wireless packets according to the same periodicity based on a respective different timing, the communication terminal comprising:

a receiving unit configured to receive a wireless packet transmitted by another communication terminal or a base station;

a determination unit configured to extract a destination address of the wireless packet that is sent from the base station to the another communication terminal, and compare a numerical value of the destination address of the another communication terminal with a numerical value of an address of the communication terminal so as to determine a transmission timing of the communication terminal based on an order of sizes of the numerical value of the destination address of the another communication terminal and the numerical value of the address of the communication terminal determined as the result of the comparison;

a transmission unit configured to periodically transmit wireless packets to the base station based on the transmission timing; and

a re-synchronization request transmission unit configured to transmit a re-synchronization signal to communication terminals when a packet error rate exceeds a predetermined value, wherein each communication terminal that receives the re-synchronization signal compares a numerical value of a destination address of a packet transmitted by another communication terminal with a numerical value of an address of the communication terminal that receives the re-synchronization signal so as to determine a transmission timing of the communication terminal that receives the re-synchronization signal based on an order of sizes of the numerical values as the result of the comparison, and

wherein the determination unit re-determines the transmission timing when receiving a re-synchronization signal from another communication terminal.

2. The communication terminal as claimed in claim 1, wherein the numerical value of the destination address of the another communication terminal and the numerical value of the address of the communication terminal are each a MAC address value.

3. The communication terminal as claimed in claim 1, wherein the determination unit is configured to determine the transmission timing of the communication terminal to be before or after the another communication terminal based on the size of the numerical value of the destination address of the another communication terminal compared to the size of the numerical value of the address of the communication terminal.

4. The communication terminal as claimed in claim 1, wherein the another communication terminal participates in communication with a third communication terminal and has a transmission timing previously established with the third communication terminal, and the receiving unit receives the wireless packet transmitted by the another communication terminal or the base station and the determination unit determines the transmission timing of the communication terminal prior to the communication terminal participating in communication and establishing transmission timing with the another communication terminal and the third communication terminal.

5. A communication method used on a communication terminal in a mobile communication system complying with a carrier sense multiple access scheme and including a plurality of communication terminals that transmit wireless packets according to the same periodicity based on a respective different timing, the method comprising:

receiving, at the communication terminal, a wireless packet transmitted by another communication terminal or a base station;

extracting, at the communication terminal, a destination address of the wireless packet that is sent from the base station to the another communication terminal, and comparing a numerical value of the destination address of the another communication terminal with a numerical value of an address of the communication terminal so as to determine a transmission timing of the communication terminal based on an order of sizes of the numerical value of the destination address of the another communication terminal and the numerical value of the address of the communication terminal determined as the result of the comparison;

periodically transmitting, at the communication terminal, wireless packets to the base station based on the transmission timing;

transmitting, at the communication terminal, a re-synchronization signal to communication terminals when a packet error rate exceeds a predetermined value, wherein each communication terminal that receives the re-synchronization signal compares a numerical value of a destination address of a packet transmitted by another communication terminal with a numerical value of an address of the communication terminal that receives the re-synchronization signal so as to determine a transmission timing of the communication terminal that receives the re-synchronization signal based on an order of sizes of the numerical values as the result of the comparison; and

re-determining, at the communication terminal, the transmission timing when receiving a re-synchronization signal from another communication terminal.