METHOD AND A DEVICE FOR ROAMING IN A LOCAL COMMUNICATION SYSTEM

• US 20130273909A1
• Filed: 07/12/2011
• Published: 10/17/2013
• Est. Priority Date: 07/26/2010
• Status: Active Grant

• Current Assignee: U-Blox AG (u-blox Holding AG)
• Original Assignee: connectBlue AB (u-blox Holding AG)
• Inventors: Bergkvist, Pelle, Nielsen, Andreas
• Granted Patent: US 9,161,202 B2
• Time in Patent Office: Days
• US Class Current: 455/432.1
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A local communication network (16) comprising a first client communication unit (10) and at least one second communication unit (12), and a method of roaming. The client communication units comprise a first interface unit (14) and a second interface unit (18) for connecting to said local communication network (16) and a remote network (20), respectively, and a bridging unit (22). The client communication units are operative in a first mode, in which said first client communication unit (10) bridges traffic between said local communication network (16) and said remote communication network (20) through a first communication path, and in a second mode, in which said second communication unit (12) scans for an alternative second communication path. A roaming control unit (24) determines whether the alternative second communication path is preferred over said first communication path. If this is the case mode of operation is switched and bridging is taken over by said second client communication unit (12).

Claims

1. A local communication network (16) comprising a first client communication unit (10) and at least one second communication unit (12), said first client communication unit (10) and said at least one second communication unit (12) each comprising a first interface unit (14) and a second interface unit (18), said first interface unit (14) being operatively connected to said local communication network and said second interface unit being operatively connected to a remote communication network (20), characterised in

that said first client communication unit (10) and said at least one second communication unit (12) comprise a bridging unit (22) capable of transparently bridging traffic between said local communication network (16) and said remote communication network (20),

that said first client communication unit (10) and said at least one second communication unit (12) are operative in a first mode, in which said first client communication unit (10) bridges traffic between said local communication network (16) and said remote communication network (20) through a first communication path, and in a second mode, in which said second communication unit (12) scans for an alternative second communication path,

that a roaming control unit (24) of said first client communication unit (10) comprises means for determining whether the alternative second communication path is preferred over said first communication path,

that the roaming control unit (24) of said first client communication unit (10) is operatively connected to the second client communication unit (12) for establishing communication through said second communication path,

that said second client communication unit (12) is operatively connected to said first client communication unit (10) for checking the operational status of the first client communication unit (10) and

that said first client communication unit (10) is arranged for switching mode of said first client communication unit (10) to said second mode, for switching mode of said second client communication unit (12) to said first mode and for activating said bridging unit (22) of said second client communication unit (12) to transparently bridge traffic between said local communication network (16) and said remote communication network (20).

2. A local communication network (16) as claimed in 1, wherein said first client communication unit (10) and said second client communication unit (12) comprise fail detection means (26).

3. A local communication network (16) as claimed in 2, wherein said fail detection means comprises a watch dog unit (26) including a timer for repeatedly transmitting poll requests, when the client communication unit operates in the second mode, and for acknowledging poll requests, when the client communication unit operates in the first mode.

4. A method of roaming in a local communication system, comprising

a) establishing a first communication path between a first client communication unit (10) of said local communication system and a remote communication network, said first client communication unit (10) operating in a first mode,

b) in a second client communication unit (12) of said local communication unit while operating in a second mode continuously scanning for a second communication path providing improved transmission properties,

c) in said second client communication unit (12) of said local communication unit preparing and establishing a second communication path,

d) executing roaming of communication from said first communication path to said second communication path,

e) disrupting communication between said first client communication unit of said local communication system and said remote communication network,

f) in said second client communication unit (12) continuously monitoring said first client communication unit (10) for fail detection and

g) in said first client communication unit of said local communication unit continuously scanning for a further communication path providing improved transmission properties.

5. A method as claimed in 4, also including the steps of continuously transmitting in said second client communication unit (12) fail detection signals to said first client communication unit (10) and changing mode of operation to said first mode on detecting a failure of said first client communication unit (10).

6. A method as claimed in 5, also including the step of transmitting a poll request from said second client communication unit (12) to said first client communication unit (10) when a predefined timeout time has elapsed.

7. A method as claimed in 4, also including the steps of providing a plurality of client communication units operating in a third mode of operation and automatically changing mode of operation from said third mode to said first mode in a first client communication unit (10).

8. A method as claimed in 4, also including the steps of providing a plurality of client communication units operating in a third mode of operation, changing mode of operation from said third mode to said first mode in a first client communication unit (10) and sending instructions from said first client communication unit (10) to a second client communication unit (12) for changing mode of operation into said second mode.