Rfid-Uwb System Connected to Wlan Infrastructure

• US 20080224869A1
• Filed: 08/08/2006
• Published: 09/18/2008
• Est. Priority Date: 08/08/2005
• Status: Active Grant

• Current Assignee: Zebra Technologies Corporation
• Original Assignee: Sandlinks Systems Ltd.
• Inventors: Kaplan, Gideon
• Granted Patent: US 7,714,698 B2
• Time in Patent Office: Days
• US Class Current: 340/572.1
• CPC Class Codes: G06K 7/10306 ultra wide band
• CPC Class Codes: H04B 1/7163 using impulse radio
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A system including a radio frequency identification (RFID) network and a wireless local area network (WLAN). The RFID network transfers ultra-wide band signals between a reader and a tag. In the wireless local area network (WLAN) an access point communicates with a WLAN transceiver using WLAN signals. The reader is operatively attached to either the wireless access point or the WLAN transceiver and the WLAN is a back haul network of the RFID network. Co-existence of the two networks is provided either by time division between the ultra-wide band signals and WLAN signals; and/or receiver isolation of said RFID network from said WLAN signals.

Claims

1. A system comprising:

(a) a radio frequency identification (RFID) network, wherein said RFID network transfers ultra-wide band signals between a reader and a tag;

(b) a wireless local area network (WLAN) including a wireless access point communicating using a plurality of WLAN signals with a WLAN transceiver, wherein said reader is operatively attached to selectably either said wireless access point or said WLAN transceiver, wherein said WLAN is a back haul network of said RFID network; and

(c) at least one mechanism which provides a function selected from the group consisting of;

(i) time division between said ultra-wide band signals and WLAN signals; and

(ii) receiver isolation of said RFID network from said WLAN signals.

2. The system, according to claim 1, wherein said wireless local area network (WLAN) operates according to a standard of Institute of Electrical and Electronics Engineers (IEEE) 802.11.

3. The system, according to claim 1, wherein said ultra-wide band signals have a bandwidth exceeding the lesser of five hundred megaHertz or twenty percent center frequency.

4. The system, according to claim 1, wherein said time division is provided using a Request to Send (RTS) WLAN signal.

5. The system, according to claim 1, wherein said time division is provided by said wireless access point which sends beacon frames at regular intervals, wherein the interval between said beacon frames includes a contention period and a contention free period, wherein said ultra wide band signals are broadcast solely during said content free period.

6. The system, according to claim 1, further comprising an RFID server application which manages said RFID network, wherein said RFID server application operatively connects to said RFID network through said WLAN.

7. The system, according to claim 1, wherein said time division is managed by an RFID server application, operatively connected to said access point through said WLAN, wherein a control command is sent from said RFID server application to said access point, thereby silencing said access point.

8. The system, according to claim 1, wherein said reader includes a medium access controller (MAC) programmed to provide said time division, wherein said MAC is synchronized with transmissions from selectably either said wireless access point or said WLAN transceiver.

9. The system, according to claim 1, wherein at least a portion of said receiver isolation is provided by increasing distance between a WLAN antenna connected to said wireless access point from an RFID antenna connected to said reader.

10. The system, according to claim 1, wherein at least a portion of said receiver isolation is provided by frequency division between said WLAN and RFID network.

11. The system, according to claim 1, wherein at least a portion of said receiver isolation is provided by a radio frequency filter.

12. The system, according to claim 1, wherein said reader and said access point are assembled in a single housing.

13. The system, according to claim 1, wherein said reader is implemented as an expansion card mounted in a mating slot in said access point.

14. The system, according to claim 1, wherein said reader includes a digital mechanism which minimizes deleterious effects of interference from said WLAN signals.

15. The system, according to claim 14, wherein said digital mechanism includes a burst-error-correcting code and an interleaver.