Local area network with wireless client freedom of movement

• US 7,532,604 B2
• Filed: 05/08/2002
• Issued: 05/12/2009
• Est. Priority Date: 05/08/2002
• Status: Active Grant

• Current Assignee: Siemens Canada Limited (Siemens AG)
• Original Assignee: Siemens Canada Limited (Siemens AG)
• Inventors: Eglin, Matthew George
• Primary Examiner(s): Phunkulh; Bob A
• Application Number:
  US10/140,629
• Publication Number:
  US 20030210671A1
• Time in Patent Office: 2,561 Days
• Field of Search: None
• US Class Current: 370/338
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/354 for supporting virtual local area networks [VLAN]
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A network with wireless connectivity, a vehicle connected to and including the network and a method of managing network data flow. The network includes multiple wireless access points, each connected to an Ethernet aggregation switch. Each Ethernet aggregation switch is virtual local area network (VLAN) aware and matches client traffic from connected access points with access VLANs. A virtual network switch maintains an association table between access VLANs and core VLANs. The virtual network switch uses the association table to manage free-form client traffic between mobile stations at access VLANs at connected Ethernet aggregation switches and appropriate core VLANs. The vehicle, including the network, may be a train with access points located trackside connecting train passengers to a public network, e.g., the Internet. Wireless devices on the train may also connect to an on-board such network.

Claims

1. A network with wireless access capability comprising:

a plurality of wireless access points;

at least one Ethernet aggregation switch, ones of said plurality of access points being connected to each said at least one Ethernet aggregation switch, each said Ethernet aggregation switch being virtual LAN (VLAN) aware and matching client traffic from connected said access points with access VLANs;

a free-form virtual network switch having at least one access port connected to each said at least one Ethernet aggregation switch and at least one core port, said free-form virtual network switch passing client traffic between access ports and core ports, said free-form virtual network switch further associating each frame of said client traffic with two VLANs, said two VLANs including an access VLAN at a respective said access port and an appropriate core VLAN at a respective core port;

a router connected to a core port and routing traffic on core VLANs between said free-form virtual network switch and a public network;

a dynamic host configuration protocol (DHCP) server managing connection between said free form virtual network switch and said public network; and

a gateway providing access control, network address translation and firewall security at said public network.

2. A network as in claim 1, the free-form virtual network switch maintaining an association table between access VLANs and core VLANs.

3. A network as in claim 1 further comprising:

at least one mobile station moving through access point reception areas, wireless connection with said network being continued with said at least one mobile station as said mobile station moves between reception areas.

4. A network as in claim 3, the free-form virtual network switch maintaining an association table between access VLANs and core VLANs and wherein as said mobile station moves between reception areas, said free form virtual network switch identifies each change of reception area and updates said association table for said each change.

5. A network as in claim 1 wherein at least two of said access points are connected to a hub forming an access point group, said hub connecting said access point group to said Ethernet aggregation switch.

6. A network as in claim 1, wherein the free-form virtual network switch comprises:

a plurality of said access ports, each said at least one Ethernet aggregation switch connected to a respective one of said plurality of access ports; and

said at least one core port is one core port, said free-form virtual network switch connecting to a router at said core port.

7. A network as in claim 6, the free-form virtual network switch maintaining an association table between said access VLANs at said plurality of access ports and said core VLANs at said core port.

8. A vehicle in wireless communication with a wireless network over access points located along a vehicle path of travel, said vehicle comprising:

an on-board wireless LAN (WLAN) bridge connecting to pathside said access points;

an on-board network including a free-form virtual network switch with a core port connected to said on-board WLAN bridge and at least one access port connected to on-board devices, said free-form virtual network switch further associating each frame of client traffic with two VLANs, said two VLANs including an access VLAN at a respective said access port and an appropriate core VLAN at a respective core port, said on-board devices connecting to a public network through said on-board network, said vehicle moving between reception areas of said pathside access points, client traffic being seamlessly routed between said public network and said on-board devices.

9. A vehicle as in claim 8 wherein said vehicle is a passenger train, said path is a train route and said on-board network comprises a plurality of on-board access points, passenger wireless devices on said train connecting to said on-board network through ones of said on-board access points.

13. A network as in claim 9 wherein said on-board network further comprises:

at least one on-board Ethernet aggregation switch, ones of said on-board access points being connected to said at least one on-board Ethernet aggregation switch, each said on-board Ethernet aggregation switch being virtual LAN (VLAN) aware and matching client traffic from connected said on-board access points with one of said access VLANs; and

an on-board free-form virtual network switch receiving client traffic from matched said access VLANs at each said connected on-board Ethernet aggregation switch and passing said client traffic to appropriate said core VLANs.

10. A network with wireless access capability, said network comprising:

a plurality of wireless access points located trackside along train tracks;

at least one Ethernet aggregation switch, ones of said plurality of access points being connected to each said at least one Ethernet aggregation switch, each said Ethernet aggregation switch being virtual LAN (VLAN) aware and matching client traffic from connected said access points with access VLANs;

a free-form virtual network switch passing client traffic between said access VLANs at each said connected Ethernet aggregation switch and appropriate core VLANs;

at least one on-board device in a train moving through access point reception areas, wireless connection with said network being continued with said at least one on-board device as said train moves between reception areas; and

an on-board network in said train connected to said on-board device, whereby on-board wireless devices connect to said network through said on-board network.

11. A network as in claim 10 wherein said on-board device is a client wireless LAN (WLAN) bridge connecting to trackside said access points.

12. A network as in claim 11 wherein said on-board network comprises a plurality of on-board access points, passenger wireless devices on said train connecting to said on-board network through ones of said on-board access points.

14. A passenger train in wireless communication with a wireless network over access points located along a train route, said passenger train comprising:

an on-board wireless LAN (WLAN) bridge connecting to pathside said access points;

an on-board network connected to said on-board WLAN bridge and on-board devices, said on-board devices connecting to a public network through said on-board network, said vehicle moving between reception areas of said pathside access points, client traffic being seamlessly routed between said public network and said on-board devices, said on-board network comprising a plurality of on-board access points, passenger wireless devices on said train connecting to said on-board network through ones of said on-board access points, said on-board network further comprising;

at least one on-board Ethernet aggregation switch, ones of said on-board access points being connected to said at least one on-board Ethernet aggregation switch, each said on-board Ethernet aggregation switch being virtual LAN (VLAN) aware and matching client traffic from connected said on-board access points with access VLANs, and

an on-board free-form virtual network switch passing client traffic between matched said access VLANs at each said connected on-board Ethernet aggregation switch and appropriate core VLANs.

15. A passenger train as in claim 14, wherein the on-board free-form virtual network switch comprises:

a plurality of access ports, each said at least one on-board Ethernet aggregation switch connected to a respective one of said plurality of on-board access ports; and

an on-board core port, said on-board free-form virtual network switch connecting to a router at said on-board core port.

16. A passenger train as in claim 15, the on-board free-form virtual network switch maintaining an association table between said access VLANs at said plurality of on-board access ports and said core VLANs at said on-board core port.