Direct mode communication method between two mobile terminals in access point controlled wireless LAN systems

• US 6,580,704 B1
• Filed: 08/26/1999
• Issued: 06/17/2003
• Est. Priority Date: 08/26/1999
• Status: Expired due to Fees

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Kuntze, Roland, Wellig, Armin, Salokannel, Juha
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): GELIN, JEAN ALLAND
• Application Number:
  US09/384,025
• Time in Patent Office: 1,391 Days
• Field of Search: 370/218, 370/231, 370/233, 370/235, 370/252, 370/253, 370/274, 370/279, 370/285, 370/293, 370/312, 370/313, 370/315, 370/332, 370/333, 370/338, 370/337, 370/349, 370/331, 370/382, 370/383, 370/395.3, 370/401, 370/402, 370/405, 370/406, 370/432, 370/471, 370/475, 370/512, 455/417, 455/513, 455/426, 455/514, 455/450, 455/515, 455/458, 455/552, 455/553, 455/575, 455/518, 455/519, 375/356
• US Class Current: 370/338
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/10 of different types
• CPC Class Codes: H04L 61/45 Network directories; Name-to-address mapping
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

There is featured a Direct Mode (DM) communication method between two mobile terminals (MTs) in access point (AP) controlled WLAN systems. The DM connection scheme calls for establishing that an initiating MT and a remote MT are associated to the same AP; establishing that the remote MT supports a DM operation feature; sending, by the AP, address identifiers of the initiating and remote MTs to the remote and initiating MTs, respectively; and sending, to the AP, RSS measurements performed by the initiating and remote MTs of MT identifying messages sent to them by the remote and initiating MTs, respectively. DM communication between the two MTs continues with exchange of information to conclusion when a MT identifying message is satisfactorily received by both MTs and when a MT identifying message of either MT is not satisfactorily received, DM communication setup is terminated.

Claims

1. In access point (AP) controlled wireless local area network (WLAN) systems, a method for direct mode (DM) communication between two mobile terminals, comprising:

(a) establishing that an initiating, first mobile terminal and a remote, second mobile terminal are associated to a same AP, including

(i) sending by the initiating, first mobile terminal a connection request to its AP with corresponding higher layer protocol address of the remote, second mobile terminal, and

(ii) look-up, by the AP, of medium access control identifier (MAC-Id) of the remote, second mobile terminal in a database of the AP,

wherein the MAC-Id of the second mobile terminal represents a unique address of that terminal within a service area of that AP, and

wherein said database contains a mapping table including the MAC-Ids and corresponding higher layer protocol addresses of all mobile terminals within the service area of that AP;

(b) establishing that the remote, second mobile terminal supports a DM operation feature as does the initiating, first mobile terminal;

(c) sending, by the AP, address identifiers of the first and second mobile terminals to the second and first mobile terminals, respectively, including granting of a channel resource slot of a frame to each of the two mobile terminals to initiate received signal strength (RSS) measurements between the two mobile terminals;

(d) sending RSS measurements performed by the first and second mobile terminals to the AP of mobile terminal identifier messages sent to them by the second and first mobile terminals, respectively; and

(e) deciding on whether to continue DM communication based on the results of the RSS measurements,

wherein DM communication between the first and second mobile terminal continues with exchange of information to conclusion when a mobile terminal identifier message is satisfactorily received by each mobile terminal and when a mobile terminal identifier message is not satisfactorily received, the DM communication setup is terminated and the AP can direct a communication linkup in which the exchange of information also flows to the AP.

2. The method according to claim 1, wherein in step (a)(ii), the MAC-Ids contained in the mapping table are represented as multi-bit local addresses within the service area of their AP.

3. The method according to claim 1, wherein the higher layer protocol addresses in said mapping table include internet protocol (IP) addresses.

4. The method according to claim 1, wherein the higher layer protocol addresses in said mapping table include Ethernet addresses.

5. The method according to claim 1, wherein in step (a)(ii) if the AP cannot locate the MAC-Id corresponding to the higher layer protocol address of the remote, second mobile terminal, DM communication setup is terminated.

6. The method according to claim 1, wherein step (b) includes:

(i) looking up, by the AP, the corresponding MAC-Id of the remote, second mobile terminal to determine if the second mobile terminal has a DM option, and

(ii) if the second mobile terminal is DM capable, the AP sends message to the second mobile terminal alerting same of DM request by the first mobile terminal at which time the second mobile terminal decides to accept/not accept initiating setup of DM, and if the second mobile terminal is not DM capable, communication between the first and second mobile terminals can instead be setup for data flow to be routed through the AP.

7. The method according to claim 6, wherein in step (c) the address identifiers include the MAC-Ids.

8. The method according to claim 7, wherein in step (d) the mobile terminal identifier message is a local unique identifier containing the MAC-Id, network identifier (Net-Id) and access point identifier (AP-Id) of the transmitting mobile terminal.

9. The method according to claim 8, wherein all information exchanged between the two mobile terminals during DM operation is encrypted, the encryption being provided via agreed on encryption key between the AP and both mobile terminals.

10. The method according to claim 1, wherein each mobile terminal includes any one of a mobile or cell phone, a WLAN PC card, and the like.

11. The method according to claim 5, wherein step (b) includes:

(i) looking up, by the AP, the corresponding MAC-Id of the remote, second mobile terminal to determine if the second mobile terminal has a DM option, and

(ii) if the second mobile terminal is DM capable, the AP sends message to the second mobile terminal alerting same of DM request by the first mobile terminal at which time the second mobile terminal decides to accept/not accept initiating setup of DM, and if the second mobile terminal is not DM capable, communication between the first and second mobile terminals can instead be setup for data flow to be routed through the AP.

12. The method according to claim 11, wherein in step (c) the address identifiers include the MAC-Ids.

13. The method according to claim 12, wherein in step (d) the mobile terminal identifier message is a unique identifier containing the MAC-Id, network identifier (Net-Id) and access point identifier (AP-Id) of the transmitting mobile terminal.

14. The method according to claim 13, wherein all information exchanged between the two mobile terminals during DM operation is encrypted, the encryption being provided via agreed on encryption key between the AP and both mobile terminals.

15. The method according to claim 14, wherein the higher layer protocol addresses in said mapping table are internet protocol (IP) addresses.

16. The method according to claim 14, wherein the higher layer protocol addresses in said mapping table are inclusive of Ethernet addresses.

17. In access point (AP) controlled wireless local area network (WLAN) systems, a mobile terminal (MT) initiated direct mode (DM) communication method between any two mobile terminals (MTs) in a service area of a same AP, comprising:

(a) sending of a request by an initiating, first mobile terminal (MT1) to the AP for a DM connection setup with a remote, second mobile terminal (MT2);

wherein the sending of a request includes sending of a direct mode flag (DM-flag) along with higher layer protocol address of remote MT2 to the AP;

(b) establishing that MT2 is DM capable as is MT1;

(c) sending, by the AP, address identifiers of MT1 and MT2 to MT2 and MT1, respectively, including granting of a channel resource slot of a frame to each of the two MTs to initiate received signal strength (RSS) measurements between the two MTs;

(d) sending RSS measurements performed by MT1 and MT2 to the AP of mobile terminal identifier messages sent to them by MT2 and MT1, respectively; and

(e) deciding on whether to continue DM communication based on the results of the RSS measurements,

wherein DM communication between MT1 and MT2 continues with exchange of information to conclusion when a mobile terminal identifier message is satisfactorily received by each MT and when a mobile terminal identifier message is not satisfactorily received, the DM communication setup is terminated and the AP can direct a communication linkup in which the exchange of information also flows to the AP.

18. The method according to claim 17, wherein said higher layer protocol address includes an internet protocol (IP) address.

19. The method according to claim 17, wherein said higher layer protocol address includes an Ethernet address.

20. The method according to claim 17, wherein step (b) includes:

(i) looking up, by the AP, a corresponding medium access control identifier (MAC-Id) address of MT2 to determine if MT2 has a DM option, and

(ii) if MT2 is DM capable, the AP sends a message to MT2 alerting MT2 of DM request by MT1, at which time MT2 decides to accept/not accept initiating setup of DM and if MT2 is not DM capable, communication between MT1 and MT2 can instead be setup for data flow to be routed through the AP.

21. The method according to claim 20, wherein in step (c) the address identifier includes the MAC-Ids.

22. The method according to claim 21, wherein in step (d) the mobile terminal identifier message is a local unique identifier containing the MAC-Id, network identifier (Net-Id) and access point identifier (AP-Id) of the transmitting mobile terminal.

23. The method according to claim 22, wherein all information exchanged between the two mobile terminals during DM operation is encrypted, the encryption being provided via agreed on encryption key between the AP and both mobile terminals.

24. The method according to claim 17, wherein each mobile terminal includes any one of a mobile or cell phone, WLAN PC card, and the like.

25. The method according to claim 23, wherein said higher layer protocol address includes an internet protocol (IP) address.

26. The method according to claim 23, wherein said higher layer protocol address includes an Ethernet address.