Method and apparatus for handoff between a wireless local area network (WLAN) and a universal mobile telecommunication system (UMTS)

• US 7,047,036 B2
• Filed: 11/14/2002
• Issued: 05/16/2006
• Est. Priority Date: 07/02/2002
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Shaheen, Kamel M., Kiernan, Brian Gregory
• Primary Examiner(s): GELIN, JEAN ALLAND
• Application Number:
  US10/294,065
• Publication Number:
  US 20040203792A1
• Time in Patent Office: 1,279 Days
• Field of Search: 455/127.4, 455/168.1, 455/436, 455/437, 455/439, 455/444, 455/454, 455/422.1, 455/426.1, 455/525, 455/62, 455/552.1, 455/553.1, 370/338, 370/466, 370/252, 370/328, 370/412, 370/352, 370/470, 370/320, 709/205, 709/235, 709/227
• US Class Current: 455/552.1
• CPC Class Codes: H04W 36/0083 Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
• CPC Class Codes: H04W 36/00837 Determination of triggering parameters for hand-off
• CPC Class Codes: H04W 36/24 Reselection being triggered by specific parameters
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 48/10 using broadcasted information
• CPC Class Codes: H04W 8/18 Processing of user or subscriber data, e.g. subscribed services, user preferences or user profiles; Transfer of user or subscriber data
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Apparatus and method for providing an automatic handoff process of a user equipment (UE) from either a wireless local area network (WLAN) to a universal mobile telecommunications system (UMTS) or from a UMTS to a WLAN. Handoffs may be initiated by the UE, based upon user preference, signal quality, comparison of location coordinates of the UE and the system to be switched to or signal quality. The available channels of one system may be broadcast to the UE by the other system or the UE may monitor channels of the system to be switched to and lock on to one. The handoff may also be initiated by the UMTS, the selection being power-based.

Claims

1. A user equipment (UE) initiated method for automated handoff of the UE from a first system to a second system, said first system being one of a universal mobile telecommunication system (UMTS) and a wireless local area network (WLAN) and the second system being a remaining one of the UMTS and WLAN, comprising:

a) said first system broadcasting a list of second systems available;

b) said UE receiving and storing a list of those second systems available within a cell in which the UE is located;

c) the UE requesting a location of those second systems available within the cell based on preferences of the user of the UE; and

d) said UE comparing its coordinates with coordinates of the second systems received from the first system and initiating a handoff procedure when the comparison operation indicates that the second system is within a preset limit.

2. A user equipment (UE) initiated handoff method for handoff of the UE from a first system to a second system wherein said first system is one of a universal mobile telecommunication system (UMTS) and a wireless local area network (WLAN) and said second system is a remaining one of the UMTS and WLAN, comprising:

a) said first system broadcasting a list of second systems available;

b) said UE receiving and storing the list;

c) said UE monitoring channels of second systems available and locking on to one channel to initiate service with the second system on said one channel;

d) said second system authenticating the UE and granting access;

e) said UE initiating the handoff to the second system through communication with the first system;

f) said first system routing data through said second system and advising the UE when the handoff process is complete; and

g) said UE assuming services with said second system responsive to a message received from the first system that the handoff process is complete.

3. The method of claim 2 wherein step (c) includes:

h) comparing the signal in said one channel with a threshold; and

i) locking on to said one channel when the signal is at least equal to said threshold.

4. A dual-mode user equipment (UE) capable of communicating with a wireless local area network (WLAN) when in a WLAN mode and with a universal mobile telecommunication system (UMTS) when in a UMTS mode for handoff of the UE from a WLAN to a UMTS, comprising:

a) said WLAN broadcasting a list of available UMTS;

b) said UE, in the WLAN mode, receiving and storing the UMTS list;

c) said UE initiating a handoff and causing radio initialization of the UMTS mode;

d) said UE in the UMTS mode providing UMTS service initialization to the UMTS;

e) said UMTS completing initialization;

f) said UE, in the WLAN mode initiating a handoff to the UMTS with the WLAN;

g) said WLAN providing for routing for data with the UMTS;

h) said WLAN advising the UE that the handoff is complete; and

i) said UE closing down the WLAN mode and resuming services with the UMTS in the UMTS mode.

5. The method of claim 4 wherein step (c) includes:

h) comparing the signal in said one channel with a threshold; and

i) locking on to said one channel when the signal is at least equal to said threshold.

6. A dual-mode user equipment (UE) capable of communicating with a wireless local area network (WLAN) when in a WLAN mode and with a universal mobile telecommunication system (UMTS) when in a UMTS mode for handoff of the UE from a WLAN to a UMTS, comprising:

a) said UE, in the WLAN mode, monitoring WLAN channels;

b) said UE locking on a WLAN channel and initiating a handoff and causing radio initialization of the UMTS mode;

c) said UE in the UMTS mode providing UMTS service initialization to the UMTS;

d) said UMTS completing initialization;

e) said UE, in the WLAN mode initiating a handoff to the UMTS with the WLAN;

f) said WLAN providing for routing for data with the UMTS;

g) said WLAN advising the UE that the handoff is complete; and

h) said UE closing down the WLAN mode and assuming services with the UMTS in the UMTS mode.

7. The method of claim 6 wherein step (b) includes:

h) comparing the signal in said one channel with a threshold; and

i) locking on to said one channel when the signal is at least equal to said threshold.

8. A user equipment (UE) initiated handoff method for use by a dual mode UE capable of operating in a wireless local area network (WLAN) mode and a universal mobile telecommunication system (UMTS) mode for handoff of the UE from a UMTS to a WLAN, comprising:

a) said UMTS broadcasting a list of available WLANs;

b) said UE, in the UMTS mode receiving and storing the list of WLANs;

c) said UE, in the UMTS mode initializing radio operation in the WLAN mode;

d) said UE, in the UMTS mode providing UE, in the WLAN mode a list of WLAN frequencies;

e) said UE, in the WLAN mode monitoring WLAN channels;

f) said UE, in the UMTS mode providing a measurement report to the UMTS;

g) said UMTS selecting a WLAN target and initiating a handoff process;

h) said UMTS providing to the UE, in the UMTS mode a target WLAN system;

i) said UE in the UMTS mode, triggering the WLAN mode to lock on to the channel of the target WLAN and initiate WLAN service;

j) said UMTS and WLAN interfacing to provide authentication for the WLAN service, said WLAN granting access to the UE in the WLAN mode;

k) said UE in the WLAN mode advising the UMTS mode that the handoff has been complete;

l) said UE in the UMTS mode acknowledging completion of the handoff; and

m) said UE, in the WLAN mode assuming services on the WLAN system.

9. A user equipment (UE) initiated system for automated handoff of the UE from a first system to a second system, said first system being one of a universal mobile telecommunication system (UMTS) and a wireless local area network (WLAN) and the second system being the remaining one of the UMTS and WLAN, comprising:

said first system having means for broadcasting a list of the second systems available;

said UE having means for receiving and storing lists of those systems available within the cell in which the UE is located;

the UE having means for requesting a location of those second systems available within the cell based on preferences of the user of the UE; and

said UE having means for comparing its coordinates with coordinates of the second systems received from the first system and initiating a handoff procedure when the comparison operation indicates that the second system is within a preset limit.

10. UE initiated handoff system for handing off the UE from a first system to a second system wherein said first system is one of a UMTS and a WLAN and said system is a remaining one of the UMTS and WLAN, comprising:

said first system having means for broadcasting a list of second systems available;

said UE having means for receiving and storing the list;

said UE having means for monitoring channels of said second system and locking on to one channel to initiate service with a second system on said channel;

said second system having means for authenticating the UE and granting access;

said UE having means for initiating the handoff to the second system through communication with the first system;

said first system having means for routing data through said second system and advising the UE when the handoff process is complete; and

said UE having means for assuming services with said second system responsive to the message received from the first system that the handoff process is complete.

11. A UE initiated handoff of a UE from a first system to a second system wherein said first system is one of a UMTS and a WLAN and said second system is a remaining one of the UMTS and WLAN, comprising:

said first system broadcasting a list of second systems channels available;

said UE receiving and storing the list;

said UE monitoring channels of said second system and locking on to one channel when a signal quality of said one channel reaches a given threshold;

said second system authenticating the UE and granting access;

said UE initiating the handoff to the second system through communication with the first system;

said first system routing data through said second system and advising the UE when the handoff process is complete; and

said UE assuming services with said second system responsive to the message received from the first system that the handoff process is complete.