System and method for transmitting data between terminals based upon progress vectors

• US 6,965,884 B2
• Filed: 05/25/2001
• Issued: 11/15/2005
• Est. Priority Date: 05/25/2000
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Honda, Ryoji, Katsuno, Yasuharu
• Primary Examiner(s): Knight, Anthony
• Assistant Examiner(s): Holmes, Michael B.
• Application Number:
  US09/866,352
• Publication Number:
  US 20020035554A1
• Time in Patent Office: 1,635 Days
• Field of Search: 706/17, 706/62, 706/45, 706/48, 455/422.1, 455/509, 455/456.1, 455/457, 455/63.1, 340/995.1, 385/31, 342/378, 342/418, 342/361, 342/362, 342/373, 342/357, 370/222, 370/261
• US Class Current: 706/17
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 40/00 Communication routing or communication path finding
• CPC Class Codes: H04W 40/20 based on geographic position or location
• CPC Class Codes: H04W 40/24 Connectivity information management, e.g. connectivity discovery or connectivity update
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

By employing easy determination logic, the amount of communication required for broadcasting and relaying is effectively reduced, and the message transmission efficiency is improved. A mobile terminal T2 includes determination logic. According to this logic, when a message is issued, via an arbitrary terminal, by a transmission source terminal T0 to a relay terminal T1, and the message is relayed by the relay terminal T1 to the terminal T2, the terminal T2 calculates an information progress vector I, which indicates the direction in which information progresses, and a terminal progress vector M, which indicates the direction in which the terminal T2 progresses. Then, the terminal T2 obtains an inner product cos θ for which the information progress vector I and the terminal progress vector M are standardized, and forwards the received message when the condition cos θ≧0 is established.

Claims

1. An information transmission method, whereby a message packet from a source terminal, said source terminal being one of multiple terminals, is relayed and forwarded by another terminal, said method comprising:

calculating an information progress vector that represents a progress of said message packet;

calculating a terminal progress vector that represents a travel performed by a specific terminal among said multiple terminals;

calculating a cosine (cos θ

) of an angle θ

formed by said information progress vector and said terminal progress vector;

determining whether said cos θ

is equal to or greater than a predetermined value; and

halting a transmission of said message packet from said specific terminal when a decision of said determining is false.

2. The information transmission method according to claim 1, further comprising:

transmitting said message packet from said specific terminal when the decision of said determining is true.

3. The information transmission method according to claim 1,

wherein said information progress vector is calculated by an arbitrary use of two or more kinds of a positional information selected from among:

a positional information for said transmission source terminal included in said information,

a positional information for other terminals, excluding said transmission source terminal, where information is delayed, and

a positional information obtained by said specific terminal; and

wherein said terminal progress vector is calculated by using current and past positional information obtained by said specific terminal.

4. The information transmission method according to claim 3, wherein said positional information is obtained by a first method whereby a positional information for a base station is obtained by a terminal that is controlled by said base station, said base station positional information used as said positional information of said terminal, or a second method for using a GPS (Global Positioning System).

5. The information transmission method according to claim 1, wherein said predetermined value is 0.

6. The information transmission method according to claim 1, wherein a density information for a terminal is obtained, and when a relationship s<

|x−

d| is established for a distance s between said specific terminal and a terminal that transmits information to said specific terminal, a communication limit distance x that is reached by a radio signal sent by said terminal, and an average inter-terminal distance d, the transmission of said message packet by said terminal is inhibited.

7. The information transmission method according to claim 6, further comprising:

requesting a transmission of a positional information by other terminals;

receiving said positional information from said other terminals; and

calculating an inter-terminal distance by using said positional information of said specific terminal and said positional information for said other terminals, and calculating an average of said inter-terminal distances and obtaining said distance d.

8. An information transmission system, wherein multiple terminals, including means for obtaining a location and means for exchanging information by radio, are provided, and wherein one of said terminals receives a message packet from one of the remaining terminals and forwards said message packet to another terminal, said system comprising:

means for calculating an information progress vector that represents a progress of said message packet;

means for calculating a terminal progress vector that represents a travel performed by a specific terminal among said multiple terminals;

means for calculating a cosine (cos θ

) of an angle θ

formed by said information progress vector and said terminal progress vector;

means for determining whether said cos θ

is equal to or greater than a predetermined value; and

means for halting transmission of said message packet from said specific terminal when a decision of said means for determining is false.

9. The information transmission system according to claim 8, further comprising:

means for transmitting said message packet from said specific terminal when the decision of said means for determining is true.

10. The information transmission system according to claim 8, further comprising:

means for calculating said information progress vector by an arbitrary use of two or more kinds of a positional information selected from among;

a positional information for a transmission source terminal included in said information,

a positional information for other terminals, excluding said transmission source terminal, where information is relayed, and

a positional information obtained by said specific terminal; and

means for calculating said terminal progress vector by using current and past positional information obtained by said specific terminal.

11. The information transmission system according to claim 10, further comprising one of:

first means for obtaining positional information for a base station at a terminal that is controlled by said base station, and for using said positional information of said base station as said positional information of said terminal, and

second means for using a GPS (Global Positioning System).

12. The information transmission system according to claim 8, wherein said predetermined value is 0.

13. The information transmission system according to claim 8, further comprising:

means for obtaining a density information for a terminal; and

means for inhibiting a transmission of said message packet when a relationship s<

|x−

d| is established for a distance s between said specific terminal and a terminal that transmits information to said specific terminal, a communication limit distance x that is reached by a radio signal sent by said terminal, and an average inter-terminal distance d.

14. The information transmission system according to claim 13, further comprising:

means for requesting a transmission of a positional information by other terminals;

means for receiving said positional information from said other terminals; and

means for calculating an inter-terminal distance by using said positional information of said specific terminal and said positional information for said other terminals, and calculating an average of said inter-terminal distances for obtaining said distance d.

15. An information terminal, including means for obtaining a location and means for exchanging message packets by radio, said information terminal comprising:

means for calculating an information progress vector that represents a progress of a message packet;

means for calculating a terminal progress vector that represents a travel performed by a specific terminal among said multiple terminals;

means for calculating a cosine (cos θ

) of an angle θ

formed by said information progress vector and said terminal progress vector;

means for determining whether said cos θ

is equal to or greater than a predetermined value; and

means for halting a transmission of said message packet from said specific terminal when a decision of said means for determining is false.

16. The information terminal according to claim 15, further comprising:

means for transmitting said message packet when the decision of said means for determining is true.

17. The information terminal according to claim 15, further comprising:

means for calculating said information progress vector by an arbitrary use of two or more kinds of a positional information selected from among;

a positional information for a transmission source terminal included in said message packet,

a positional information for other terminals, excluding said transmission source terminal, where information is relayed, and

a positional information obtained by said information terminal; and

means for calculating said terminal progress vector by using current and past positional information obtained by said information terminal.

18. The information terminal according to claim 15, wherein said predetermined value is 0.

19. The information terminal according to claim 15, further comprising:

means for requesting a transmission of positional information by other terminals;

means for receiving said positional information from said other terminals;

means for calculating an inter-terminal distance by using said positional information of said information terminal and said positional information for said other terminals, and calculating an average of said inter-terminal distances for obtaining an average inter-terminal distance d; and

means for inhibiting a transmission of said information when a relationship s<

|x−

d| is established for a distance s between said information terminal and a terminal that transmits information to said information terminal, a communication limit distance x that is reached by a radio signal sent by said terminal, and an average inter-terminal distance d.

20. A signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform a method of receiving a message packet from a terminal and forwarding said message packet to another terminal, said program of machine-readable instructions comprising:

an information progress vector calculator module for calculating an information progress vector that represents a progress of said message packet;

a terminal progress vector calculator module for calculating a terminal progress vector that represents a travel performed by said information terminal among said multiple terminals;

a cosine calculator for calculating a cosine (cos θ

) of an angle θ

formed by said information progress vector and said terminal progress vector;

a decision module for determining whether said cos θ

is equal to or greater than a predetermined value; and

a transmit control module for transmitting said information when a decision output of said decision module is true and for halting transmission of said message packet when the an output of said decision module is false.

21. A message packet distribution method in a radio communication distribution system, said method comprising:

receiving, in a receiving terminal, a message packet having been transmitted from a source terminal;

calculating, in said receiving terminal, an information progress vector representing a direction said received message packet is progressing away from said source terminal;

determining, in said receiving terminal, whether said received message packet should be forwarded, based on said information progress vector; and

transmitting said received message packet from said receiving terminal based on said determining.

22. The message packet transmission method of claim 21, further comprising:

calculating, in said receiving terminal, a terminal progress vector representing a motion of said receiving terminal; and

using said terminal progress vector as a factor in said determining whether said received message packet should be forwarded.

23. A terminal in a radio communication distribution system, said terminal comprising:

a receiver that receives a message packet having been transmitted from a source terminal;

an information progress vector calculator that calculates an information progress vector representing a direction said received message packet is progressing away from said source terminal;

a decision module that determines whether said received message packet should be forwarded, based on said information progress vector; and

a transmitter that transmits said received message packet based on said determining by said decision module.

24. The terminal of claim 23, further comprising:

a terminal progress vector calculator that calculates a terminal progress vector representing a motion of said receiving terminal,

wherein said decision module uses said terminal progress vector as a factor in said determining whether said received message packet should be forwarded.