US 6,580,704 B1Granted

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

AssigneeNokia Corporation

InventorsArmin Wellig, Roland Kuntze, Juha Salokannel

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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.

Claims26

Dependent claims

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.

8 more elements

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.

5 more elements

Dependencies are inferred from the claim text.