Mobile internet service system for long distance trains

• US 9,258,759 B2
• Filed: 05/21/2014
• Issued: 02/09/2016
• Est. Priority Date: 02/17/2012
• Status: Active Grant

• Current Assignee: City University of Hong Kong
• Original Assignee: City University of Hong Kong
• Inventors: Jia, Weijia, Tso, Fung Po
• Primary Examiner(s): Qureshi, Afsar M
• Application Number:
  US14/284,311
• Publication Number:
  US 20140254378A1
• Time in Patent Office: 629 Days
• Field of Search: 370235-401
• US Class Current: 1/1
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04W 28/0236 radio quality, e.g. interference, losses or delay
• CPC Class Codes: H04W 40/14 based on stability
• CPC Class Codes: H04W 84/005 Moving wireless networks

Abstract

Embodiments described herein generally relate to providing communication services to client devices in a transport system. In some examples, methods of providing communication services to client devices in a transport system are described. The methods can include exchanging, among a multiple number of routers provided in a transport system, status information of each of the multiple number of routers. The methods can also include receiving, at a given router included in the multiple number of routers, a communication addressed to a remote server accessible through a first network. The communication may be received from a client device connected to the given router through a second network different than the first network. The methods can also include, based on the status information, routing the communication to the remote server through at least the given router and the first network.

Claims

1. A method of providing communication services to client devices in a transport system, the method comprising:

receiving, at a given router among a plurality of routers provided in the transport system, status information of one or more of the plurality of routers; and

based on the status information, the given router routing communications between a remote server accessible through a first network and a client device connected to the given router through a second network different than the first network.

2. The method of claim 1, wherein the given router routing communications between the remote server accessible through the first network and the client device connected to the given router through the second network includes:

the given router tunneling a first communication to the remote server through the first network; and

the given router forwarding a second communication to a neighbor router included in the plurality of routers, wherein the second communication is tunneled to the remote server through the first network by the neighbor router or another router included in the plurality of routers.

3. The method of claim 1, further comprising the given router routing communications to the remote server through a proxy server.

4. The method of claim 1, further comprising the given router performing a network address translation (NAT) on a private source address and private source port included in a communication from the client device to the remote server to obtain a public source address and public source port corresponding to the given router, wherein the public source address and public source port are included in the communication routed to the remote server.

5. The method of claim 4, further comprising:

the given router maintaining a translation table;

the given router receiving a return communication from the remote server;

the given router performing, using the translation table, a deNAT on a public destination address and public destination port included in the return communication to obtain a private destination address and private destination port; and

when the private destination address and the private destination port respectively match the private source address and the private source port included in the communication from the client device, the given router forwarding the return communication to the client device.

6. The method of claim 1, further comprising the given router sending status information of the given router to others of the plurality of routers.

7. The method of claim 6, wherein the given router sending status information of the given router to others of the plurality of routers comprises the given router sending status information of the given router to others of the plurality of routers according to a predefined, periodic schedule or in response to detecting a change in a connection status of the given router to the first network.

8. The method of claim 6, wherein:

the plurality of routers are connected in a bus topology;

the given router sending status information of the given router to others of the plurality of routers comprises the given router sending status information of the given router to one or two neighbor routers connected immediately adjacent to the given router in the bus topology; and

the given router receiving status information of one or more of the plurality of routers comprises the given router receiving status information from the one or two neighbor routers connected immediately adjacent to the given router in the bus topology.

9. A method of providing communication services to client devices in a transport system, the method comprising:

exchanging, among a plurality of routers in the transport system, status information of the plurality of routers, wherein the plurality of routers each include a network interface configured to communicate over a first network over which a remote server is accessible and wherein the status information for each router i includes at least one of;

a loading factor W_i of the router i;

a status of a network interface of the router i to the first network;

an aggregated loading factor WF_i of all routers connected, in a bus topology, forward of the router i;

a number NF_i of all available routers connected, in the bus topology, forward of the router i;

an aggregated loading factor WB_i of all routers connected, in the bus topology, backwards of the router i; and

a number NB_i of all available routers connected, in the bus topology, backwards of the router i;

calculating, by the plurality of routers, a corresponding unbalance factor d_i based on the status information; and

each time a client device initiates a new communication session with a given router among the plurality of routers over a second network to communicate with the remote server, determining, by the given router, whether to forward the new communication session to a neighbor router or tunnel the new communication session to the remote server over the first network based on the status information and the corresponding unbalance factor d_i of the given router.

10. The method of claim 9, wherein the given router determining whether to forward the new communication session to the neighbor router or tunnel the new communication session to the remote server over the first network comprises:

the given router determining whether the status of the network interface of the given router to the first network indicates that the network interface of the given router is operational;

if the status of the network interface of the given router to the first network indicates that the network interface of the given router is operational;

the given router calculating a new unbalance factor D₁ for the given router that would result from the given router tunneling the new communication session to the remote server through the first network; and

if the new unbalance factor D₁ is less than or equal to an old unbalance factor d₁ for the given router, the given router tunneling the new communication session to the remote server through the first network;

or

if the status of the network interface of the given router to the first network indicates that the network interface if the given router is not operational, or if the new unbalance factor D₁ is greater than the old unbalance factor d₁;

the given router calculating a new unbalance factor D₂ and D₃ for a first neighbor router and a second neighbor router, respectively, that would result from the first neighbor router or the second neighbor router tunneling the new communication session to the remote server through the first network, wherein each of the first neighbor router and the second neighbor router is connected immediately adjacent to the given router in the bus topology;

forwarding the new communication session to the first neighbor router if D₂ is smaller than D₃;

or

forwarding the new communication session to the second neighbor router if D₃ is smaller than D₂.

11. The method of claim 9, wherein the unbalance factor d_i is calculated according to a formula d_i=max(WF_i/NF_i, W_i, WB_i/NB_i)−

min(WF_i/NF_i, W_i, WB_i/NB_i).

12. The method of claim 9, wherein each ongoing communication session on the given router i has a weight, and wherein the loading factor W_i of the router i is a sum of the weights of all ongoing communication sessions on the router i.

13. The method of claim 12, wherein each of the plurality of routers is configured to maintain an ongoing communication session on a respective router so long as:

a difference between the loading factor of the respective router and WF_i/NF_i or between the loading factor of the respective router and WB_i/NB_i is less than a threshold value;

a difference between the loading factor of the respective router and a loading factor of an immediately previous neighbor router in the bus topology is smaller than the threshold value; and

a difference between the loading factor of the respective router and a loading factor of an immediately next neighbor router in the bus topology is smaller than the threshold value.

14. The method of claim 13, wherein the threshold value is two times a minimum ongoing session weight of the respective router.

15. The method of claim 13, further comprising, if the difference between the loading factor of the respective router and WF_i/NF_i or between the loading factor of the respective router and WB_i/NB_i is greater than or equal to the threshold value:

re-routing at least one ongoing communication session from the respective router to the immediately previous neighbor router if WF_i/NF_i is less than WB_i/NB_i;

or

re-routing at least one ongoing communication session from the respective router to the immediately next neighbor router if WB_i/NB_i is less than WF_i/NF_i.

16. The method of claim 13, further comprising, if the difference between the loading factor of the respective router and the loading factor of the immediately previous neighbor router is greater than or equal to the threshold value, re-routing at least one ongoing communication session from the respective router to the immediately previous neighbor router.

17. The method of claim 13, further comprising, if the difference between the loading factor of the respective router and the loading factor of the immediately next neighbor router is greater than or equal to the threshold value, re-routing at least one ongoing communication session from the respective router to the immediately next neighbor router.

18. A router communicatively coupled to a plurality of routers in a transport system and configured to provide communication services to one or more client devices present in the transport system, wherein the router comprises:

a first network interface configured to communicate over a first network;

a second network interface configured to communicate over a second network different from the first network;

a control module configured to execute computer-executable instructions; and

a non-transitory computer-readable storage medium having computer-executable instructions stored thereon that are executable by the control module to cause the router to perform operations comprising;

generating status information for the router;

receiving status information at the router from one or more of the plurality of routers; and

based on the status information of the router and the status information of the one or more of the plurality of routers, routing communications between a remote server accessible through the first network and a client device connected to the router through the second network.

19. The router of claim 18, wherein the router is communicatively coupled to the plurality of routers in a bus topology over a Wireless Distribution System (WDS) network.

20. The router of claim 18, wherein:

the first network comprises a wireless wide area network (WAN), including at least one of a Universal Mobile Telecommunications System (UMTS) network, a High Speed Packet Access (HSPA) network, a Worldwide Interoperability for Microwave Access (WiMAX) network, or a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) network; and

the second network comprises a wired or wireless local area network (LAN).