Method for a synchronized hand off from a cellular network to a wireless network and apparatus thereof

• US 20040081117A1
• Filed: 10/29/2002
• Published: 04/29/2004
• Est. Priority Date: 10/29/2002
• Status: Abandoned Application

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Malek, Charles John, Pan, Shaowei
• Application Number:
  US10/282,654
• Publication Number:
  US 20040081117A1
• Time in Patent Office: Days
• US Class Current: 370/324
• CPC Class Codes: H04B 1/7073 Synchronisation aspects
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 2201/70715 with application-specific features
• CPC Class Codes: H04B 7/2696 Over the air autonomous synchronisation, e.g. by monitoring network activity H04B7/2693 takes precedence
• CPC Class Codes: H04J 3/0638 Clock or time synchronisation among nodes; Internode synchronisation synchronization for ring networks H04L12/422; data switching networks with synchronous transmission H04L12/43
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/1446 wherein at least one of the networks is unlicensed
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A method and apparatus for synchronized hand off from a cellular network (138) to a wireless network (100) includes an antenna (110) capable of receiving a synchronization channel and a pilot channel (112). Within the wireless network (100) is an access point (104) and a cellular timing recovery receiver (106) coupled to the antenna (110). The cellular timing recovery receiver (106) receives the synchronization channel and the pilot channel (112), which are provided to the access point (104) from a cellular base station (114). The cellular timing recovery receiver (106) thereupon generates a clock pulse (120) and a clock setting signal (122) which are provided to the access point (104), which are utilized to synchronize an internal clock with respect to the timing of the cellular base station (114). Thereupon, the wireless area network (100) may be synchronized with a cellular network (138) message information (150c).

Claims

1. A wireless area network access point comprising:

an antenna, such that the antenna receives an incoming signal having a synchronization channel and a pilot channel; and

a code division multiple access cellular timing recovery receiver operably coupled to the antenna, wherein the code division multiple access cellular timing recovery receiver receives the synchronization channel and the pilot channel of the incoming signal from the antenna.

2. The wireless area network access point of claim 1 further comprising:

a radio frequency coupling device operably coupled to and disposed between the antenna and the code division multiple access cellular timing recovery receiver.

3. The wireless area network access point of claim 1 wherein the incoming signal is a radio frequency signal.

4. The wireless area network access point of claim 3 such that the antenna receives the incoming signal from a cellular base station.

5. The wireless area network access point of claim 1, wherein the code division multiple access cellular timing recovery receiver comprises:

a front end receiver that receives a forward link from the antenna;

a rake receiver coupled to the front end receiver, wherein the rake receiver receives an internal frequency output signal from the front end receiver;

an inverse fast Hadamard transformer operably coupled to the rake receiver, wherein the inverse fast Hadamard transformer receives a demodulated base band signal from the rake receiver;

a synchronization channel decoder operably coupled to the inverse fast Hadamard transformer such that the synchronization channel decoder receives an encoded synchronization channel from the inverse fast Hadamard transformer and produces therefrom a clock setting signal; and

a digital phase lock loop operably coupled to the rake receiver such that the digital phase lock loop receives the internal frequency output signal from the rake receiver and produces therefrom a clock pulse.

6. The wireless area network access point of claim 5 further comprising:

a wireless access network circuit operably coupled to the digital phase lock loop and receives the clock pulse therefrom and operably coupled to the synchronization channel decoder and receives the clock setting signal therefrom.

7. A method for a synchronized hand off from a cellular network to a wireless area network, the method comprising:

within an access point of the wireless area network, receiving an incoming signal having a synchronization channel and a pilot channel;

providing the synchronization channel and the pilot channel to a code division multiple access cellular timing recovery receiver disposed within the access point; and

generating a clock pulse using the synchronization channel and the pilot channel, wherein the clock pulse may be used for synchronization of the wireless network with the cellular network.

8. The method of claim 7, wherein the synchronization channel and the pilot channel are provided from a cellular base station.

9. The method of claim 8 further comprising:

providing the clock pulse to a wireless area network circuit to produce a wireless network output signal.

10. The method of claim 9 further comprising:

receiving a message signal from a first communication device, wherein the first communication device also provides the message signal to the cellular base station such that that the cellular base station provides a cellular message signal to a second communication device across the cellular network.

11. The method of claim 10 further comprising:

providing the message signal to the wireless area network circuit such that the wireless area network circuit generates a wireless network message signal;

transmitting the wireless network message signal to the second communication device in synchronization with the cellular message signal.

12. The method of claim 7 wherein the cellular timing recovery receiver is a code division multiple access cellular timing recovery receiver.

13. The method of claim 12 wherein the step of providing the synchronization channel and the pilot channel to the code division multiple access cellular timing recovery receiver disposed within the access point further comprises:

receiving a forward link containing the synchronization channel and the pilot channel;

generating an intermediate frequency output signal;

generating a demodulated baseband signal using the intermediate frequency output signal;

generating a clock pulse using the intermediate frequency output signal;

decoding the synchronization channel using the demodulated baseband signal; and

generating a clock setting signal in response to the decoded synchronization channel.

14. The method of claim 13 further comprising:

providing the clock pulse to a wireless area network circuit; and

providing the clock setting signal to the wireless area network circuit.

15. A method for a synchronized hand off between a first communication network and a second communication network such that a message signal from a first communication device is provided to a second communication device across the first communication network, the method comprising:

receiving the message signal from the first communication device;

receiving a synchronization channel and a pilot channel from the first communication network;

providing the synchronization channel and the pilot channel to a timing recovery receiver;

generating a clock pulse using the synchronization channel and the pilot channel and a clock setting signal using the synchronization channel; and

providing the clock and the clock setting signal to a second communication network circuit such that the message signal may be provided to the second communication device in synchronization with the first communication network.

16. The method of claim 15 wherein the synchronization channel and the pilot channel are received by a second communication network antenna of the second communication network and the synchronization channel and the pilot channel are provided to the timing recovery receiver from the second communication antenna.

17. The method of claim 16 wherein prior to providing the synchronization channel and the pilot channel to the timing recovery receiver, the synchronization channel, the pilot channel and the message signal are provided to a radio frequency coupling device.

18. The method of claim 15 wherein the first communication network is a cellular network and the second communication network is a wireless area network.

19. The method of claim 18 wherein the synchronization channel and the pilot channel are provided to the wireless area network from a cellular base station.