Method, System and Arrangements for Setting Up and Maintaining a WLAN Connection within predictably moving vehicles

• US 20090219900A1
• Filed: 11/29/2006
• Published: 09/03/2009
• Est. Priority Date: 11/29/2005
• Status: Active Grant

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Koivisto, Karl O., Kuoppala, Mika, Kaaja, Harald, Karhiniemi, Marko, Kokkinen, Heikki
• Granted Patent: US 8,681,753 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: B61L 15/0027 Radio-based, e.g. using GSM-R
• CPC Class Codes: B61L 27/70 Details of trackside communication
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 36/324 by mobility data, e.g. speed data
• CPC Class Codes: H04W 40/18 based on predicted events
• CPC Class Codes: H04W 84/005 Moving wireless networks

Abstract

Setting up and maintaining wireless communication connections with end user'"'"'s terminals (301) on board a predictably moving vehicle (303) is shown with mechanisms for correcting for Doppler effects. A central device (302) within the vehicle (303) acts as a hub of a wireless network. There are a number of fixed transceivers (304). A connection arrangement (305, 306, 705, 706, 1001, 1101, 1122) connects the fixed transceivers (304) to an external packet-switched data network. The central device (302) within the vehicle (303) is a mobile router (302) equipped with routing capability (407). The connection arrangement (305, 306, 705, 706, 1001, 1101, 1122) includes a connection (705, 706, 1001) between a number of fixed transceivers (304) and a fixed central device (305) The fixed central device (305) has routing capability (1007), and together with the mobile router (302) implement routing of packets between the packet-switched network and an end user'"'"'s terminal (301).

Claims

1. A mobile router

configured to be located within a predictably moving vehicle and adapted to act as a hub of a wireless network on board the vehicle,

and wherein the mobile router is adapted to communicate with a fixed transceiver in a cell of which the mobile router resides,

and wherein the mobile router is equipped with routing capability,

and wherein said mobile router is adapted to implement routing of data packets between a packet-switched data network and an end user'"'"'s terminal operative in the wireless network on board the vehicle,

and wherein said mobile router is adapted to perform a corrective measure in a radio connection between a transceiver of said mobile router and said fixed transceiver on the basis of a speed indication received from speed determination unit, which corrective measure comprises at least one of Doppler shift correction of frequency and dynamical determination of packet size.

2. The mobile router according to claim 1, wherein as said speed determination unit, the mobile router comprises a positioning system receiver.

3. The mobile router according to claim 1, wherein as said speed determination unit, the mobile router comprises a connection from a train speedometer to said mobile router.

4. A method comprising:

establishing a wireless network around a mobile router on board a predictably moving vehicle,

setting up a radio connection between a transceiver of the mobile router and one of a number of fixed transceivers, each of which has a geographical coverage area that constitutes a cell,

utilizing said radio connection to transfer data packets between the mobile router on board the vehicle and an external packet-switched data network,

maintaining routing tables at said mobile router on board the vehicle, in order to route data packets between the packet-switched data network and an end user'"'"'s terminal operative in the wireless network on board the vehicle,

determining a speed at which the mobile router on board the vehicle is moving relative to a fixed transceiver, and

performing a corrective measure in said radio connection on the basis of speed so determined, which corrective measure comprises at least one of Doppler shift correction of frequency and dynamical determination of packet size.

5. The method according to claim 4, wherein for enabling continuous connections between the mobile router on board the vehicle and the external packet-switched data network, the method comprises:

directing downlink packets to a fixed transceiver with which the mobile router on board the vehicle is communicating, and additionally to another fixed transceiver, which is that fixed transceiver with which the mobile router on board the vehicle will be communicating next with the highest probability.

6. The method according to claim 4, wherein in a situation where:

a number of fixed transceivers belong to a subnetwork,

there are several consecutive subnetworks along a predicted route of movement of the vehicle and

the mobile router on board the vehicle is predictably moving from a cell of a fixed transceiver of a first subnetwork to a cell of an adjacent fixed transceiver belonging to a second subnetwork;

the method comprises tunnelling downlink data packets destined to the mobile router on board the vehicle from said first subnetwork to said second subnetwork for further transmission from said fixed transceiver belonging to said second subnetwork to the mobile router on board the vehicle.

7. Apparatus comprising:

means for establishing a wireless network around a mobile router on board a predictably moving vehicle;

means for setting up a radio connection between a transceiver of the mobile router and one of a number of fixed transceivers, each of which has a geographical coverage area that constitutes a cell;

means for utilizing said radio connection to transfer data packets between the mobile router on board the vehicle and an external packet-switched data network;

means for maintaining routing tables at said mobile router on board the vehicle, in order to route data packets between the packet-switched data network and an end user'"'"'s terminal operative in the wireless network on board the vehicle;

means for determining a speed at which the mobile router on board the vehicle is moving relative to a fixed transceiver; and

means for performing a corrective measure in said radio connection on the basis of speed so determined, which corrective measure comprises at least one of Doppler shift correction of frequency and dynamical determination of packet size.