Method of setting up AD HOC local area network, method of communicating using said network, and terminal for use with said network

• US 6,415,330 B1
• Filed: 04/27/2000
• Issued: 07/02/2002
• Est. Priority Date: 12/27/1996
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Okanoue, Kazuhiro
• Primary Examiner(s): Geckil, Mehmet B.
• Assistant Examiner(s): VU, THONG H
• Application Number:
  US09/559,994
• Time in Patent Office: 796 Days
• Field of Search: 709/228, 709/222, 709/250, 709/227, 709/245, 455/63, 455/422, 455/552, 455/557, 370/337, 370/329, 370/349, 370/338, 370/311, 345/339, 345/326, 345/329
• US Class Current: 709/245
• CPC Class Codes: H04L 12/1836 with heterogeneous network architecture
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/1854 with non-centralised forwarding system, e.g. chaincast
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04W 24/06 Testing, supervising or monitoring using simulated traffic
• 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 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

An ad hoc LAN is set up in an environment in which there simultaneously exist a backbone-connected LAN connected by a high-speed backbone network and an ad hoc LAN not connected to the backbone network, wherein the ad hoc LAN is capable of communicating simultaneously with both LANs. An ad hoc LAN is defined as one multicast group used within the backbone network and backbone-connected LAN. This makes it possible for a terminal, which is connected to the ad hoc LAN and backbone-connected LAN simultaneously so that it may communicate with both LANs, to participate in the ad hoc LAN in the same manner as it would participate in a multicast group of a conventional backbone-connected LAN. As a result, the terminal construction is simplified and the terminal can be connected to an ad hoc LAN and backbone-connected LAN simultaneously.

Claims

1. A terminal connectable to a backbone-connected LAN and to an ad hoc LAN simultaneously in an environment

(a) in which there simultaneously exist a plurality of backbone-connected LANs interconnected by a backbone network via routers and each having a plurality of terminals (referred to as “

terminal group 1”

) connected thereto, and a plurality of ad hoc LANs unconnected to said backbone network and each having a plurality of terminals (referred to as “

terminal group 2”

) connected thereto;

(b) wherein a plurality of multicast groups, in which all or part of the terminal groups 1 are members, are set up dynamically within a network constituted by said backbone network and said backbone-connected LANs;

(c) identifiers which identify respective ones of said multicast groups are defined for said multicast groups;

(d) communication between the members constituting said multicast groups is performed using the identifiers which identify said multicast groups; and

(e) all or part of the terminal groups 2 are capable of communicating simultaneously not only with terminals connected to said ad hoc LANs to which said terminal groups 2 are connected but also with terminals connected to said backbone-connected LANs;

(f) said terminal being capable of communicating simultaneously not only with terminals connected to said ad hoc LANs but also with terminals connected to said backbone-connected LAN;

(g) said terminal comprising;

(1) a transceiver for ad hoc LAN purposes for sending signals to and receiving signals from transmission media constituting said ad hoc LANs;

(2) a transceiver for backbone-connected LAN purposes for sending signals to and receiving signals from transmission media constituting said backbone-connected LANs;

(3) a device driver for ad hoc LAN purposes corresponding to said transceiver for ad hoc LAN purposes;

(4) a device driver for backbone-connected LAN purposes corresponding to said transceiver for backbone-connected LAN purposes; and

(5) a device driver controller for sending signals to and receiving signals from both said device driver for ad hoc LAN purposes and said device driver for backbone-connected LAN purposes via a predetermined interface (referred to as “

interface 1”

), and sending signals to and receiving signals from network layer software via said interface 1.

2. The terminal according to claim 1, wherein said device driver controller of the terminal connected simultaneously to said backbone-connected LAN and said ad hoc LAN

(a) manages an address list which includes other terminals connected to said ad hoc LAN to which said terminal is connected as well as identifiers of existing multicast groups; and

(b) in a case where said terminal transmits data, delivers the transmission data to said device driver for ad hoc LAN purposes if a destination address exists in said address list and to said device driver for backbone-connected LAN purposes if the said destination address does not exist in said address list.

3. The terminal according to claim 2, wherein the address list is created as follows:

(a) each terminal connected to said ad hoc LAN periodically transmits an address announcement message to a predetermined destination or destinations, wherein this address announcement message includes the address of said transmitting terminal and the identifier of said participating multicast group within said ad hoc LAN; and

(b) at any of terminals which received said address announcement message, the address list is created based upon the address of said transmitting terminal and the identifier of said participating multicast group within said ad hoc LAN, said address and said identifier being included in the address announcement message received by said terminals.

4. The terminal according to claim 3, wherein said device driver controller of the terminal connected simultaneously to said backbone-connected LAN and said ad hoc LAN

(a) has said address list;

(b) in a case where said terminal transmits data to a multicast group within said ad hoc LAN,

said device driver controller creates an encapsulation header by using an identifier which identifies said ad hoc LAN and the address of said terminal, to add said encapsulation header onto the transmission data, and delivers the transmission data to said device driver; and

(c) upon receiving data from a multicast group within said an ad hoc LAN from said device driver, said device controller removes said encapsulation header from the received data and delivers the data to said network layer software of said terminal.

5. A system of ad hoc LAN communication in an environment in which

(a) there simultaneously exist a plurality of backbone-connected LANs interconnected by a backbone network via routers and each having a plurality of terminals (referred to as “

terminal group 1”

) connected thereto, and a plurality of ad hoc LANs unconnected to said backbone network and each having a plurality of terminals (referred to as “

terminal group 2”

) connected thereto;

(b) wherein a plurality of multicast groups, in which all or part of the terminal groups 1 are members, are set up dynamically within a network constituted by said backbone network and said backbone-connected LANs;

(c) identifiers which identify respective ones of said multicast groups are defined for said multicast groups;

(d) communication between the members constituting said multicast groups is performed using the identifiers which identify said multicast groups; and

(e) it is so arranged that all or part of the terminal groups 2 are capable of communicating simultaneously not only with terminals connected to said ad hoc LANs to which said terminal groups 2 are connected but also with terminals connected to said backbone-connected LANs;

(f) said method comprising the steps of;

(f1) adding a network layer header, which is created based upon a destination address and an address of transmitting terminal, onto transmission data; and

(f2) communicating the transmission data, onto which said network layer header has been added, using a packet encapsulated by an encapsulation header created employing the identifier identifying -an ad hoc LAN as a destination and employing the address of the transmitting terminal as the source of transmission.