Systems and methods for mobile phone location with digital distributed antenna systems

• US 8,346,278 B2
• Filed: 09/09/2009
• Issued: 01/01/2013
• Est. Priority Date: 01/13/2009
• Status: Active Grant

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Wala, Philip M., Zavadsky, Dean
• Primary Examiner(s): Arevalo, Joseph
• Application Number:
  US12/555,923
• Publication Number:
  US 20100178936A1
• Time in Patent Office: 1,210 Days
• Field of Search: 370/401, 370/503, 370/508, 370/906, 370/907, 370/347, 370/345, 370/512, 370/210, 370/320, 455/3.01, 455/414.1, 455/517, 455/456.1, 455/456.2, 455/552.1, 455/323, 455/424, 455/16, 455/78, 455/88, 455/450, 709/224, 709/231
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/0054 of actual mobile position, i.e. position calculation on base station
• CPC Class Codes: G01S 5/0221 Receivers
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 76/50 for emergency connections

Abstract

Methods and systems for mobile phone location within a digital distributed antenna system (DAS) are provided. In one embodiment, a method comprises: receiving a request for location services from a subscriber unit located within a digital DAS, the digital DAS including a first partition of bandwidth for transporting digitized RF signals of one or more modulated signals and a second partition of bandwidth for an Ethernet pipe transporting IP formatted data; routing the request for location services to a subscriber locator center; instructing locator receivers within a geographical area of the digital DAS to listen for a signal from the subscriber unit; listening for the signal at a first locator receiver; when the signal is observed, recording a time the signal was received and generating subscriber unit ranging data; and transmitting subscriber unit ranging data back to the subscriber locator center in an IP formatted message via the Ethernet pipe.

Claims

1. A method for gathering location data within a geographical area of a digital distributed antenna system, the method comprising:

receiving a request for location services from a subscriber unit located within the geographical area of the digital distributed antenna system, the digital distributed antenna system including a first partition of bandwidth for transporting digitized radio frequency (RF) signals of one or more modulated signals, the digital distributed antenna system further including a second partition of bandwidth for an Ethernet pipe for transporting Internet Protocol (IP) formatted data;

routing the request for location services to a subscriber locator center, wherein routing the request for location services to the subscriber locator center comprises transporting the request for location services via the first partition of bandwidth for transporting digitized RF signals;

instructing a plurality of locator receivers within the geographical area of the digital distributed antenna system to listen for a signal from the subscriber unit;

listening for the signal from the subscriber unit at a first locator receiver of the plurality of locator receivers;

when the signal is observed by the first locator receiver, recording a time the signal was received and generating subscriber unit ranging data; and

transmitting subscriber unit ranging data back to the subscriber locator center in an IP formatted message via the Ethernet pipe provided by the digital distributed antenna system.

2. The method of claim 1 wherein the first locator receiver is located at a first remote unit of the digital distributed antenna system.

3. The method of claim 1 wherein the first locator receiver is located at a host unit of the digital distributed antenna system.

4. The method of claim 1 wherein listening for the signal from the requesting mobile phone at a first locator receiver of the locator receivers further comprises:

receiving an analog RF signal.

5. The method of claim 1 further comprising:

receiving an analog RF signal;

generating a baseband digital signal from the analog RF signal; and

wherein listening for the signal from the subscriber unit at the first locator receiver further comprises processing the baseband digital signal to make a timing measurement.

6. The method of claim 1 further comprising:

receiving an analog RF signal;

generating an intermediate frequency digital signal from the analog RF signal; and

wherein listening for the signal from the subscriber unit at the first locator receiver further comprises processing the intermediate frequency digital signal to make a timing measurement.

7. A remote unit for a digital distributed antenna system, the remote unit comprising:

at least one digital to analog radio frequency transceiver module for generating a digital radio frequency signal from an analog radio frequency signal received from one or more subscriber units;

a locator receiver receiving the analog radio frequency signal, the locator receiver generating subscriber unit ranging data for a selected first subscriber unit of the one or more subscriber units from the analog radio frequency signal, wherein the locator receiver outputs the subscriber unit ranging data as Internet Protocol (IP) formatted data;

a serial radio frequency module coupled to receive the digital radio frequency signal from the at least one digital to analog radio frequency transceiver module, the serial radio frequency module further comprising an interface for receiving the IP formatted data from the locator receiver;

wherein the serial radio frequency module outputs a serial stream to a host unit, the serial stream comprising a bandwidth with a first partition for transporting the digital radio frequency signal to the host unit and a second partition implementing an Ethernet pipe for transporting the subscriber unit ranging data to the host unit as IP formatted data; and

wherein the interface for receiving the IP formatted data from the locator receiver provides bidirectional access to the Ethernet pipe.

8. The remote unit of claim 7, wherein the locator receiver formats the subscriber unit ranging data for routing to a subscriber locator center over an Internet Protocol (IP) network.

9. The remote unit of claim 7, wherein the selected first subscriber unit is selected by the locator receiver based on instructions received from a subscriber locator center via the Ethernet pipe.

10. A remote unit for a digital distributed antenna system, the remote unit comprising:

at least one digital to analog radio frequency transceiver module for generating a digital radio frequency signal from an analog radio frequency signal received from one or more subscriber units;

a serial radio frequency module coupled to receive the digital radio frequency signal from the at least one digital to analog radio frequency transceiver module;

a locator receiver coupled to the serial radio frequency module and receiving a loop-back of the digital radio frequency signal from the serial radio frequency module, the locator receiver generating subscriber unit ranging data for a selected first subscriber unit of the one or more subscriber units from the digital radio frequency signal, wherein the locator receiver outputs the subscriber unit ranging data to the serial radio frequency module as Internet Protocol (IP) formatted data;

wherein the serial radio frequency module outputs a serial stream to a host unit, the serial stream comprising a bandwidth with a first partition for transporting the digital radio frequency signal to the host unit and a second partition implementing an Ethernet pipe for transporting the subscriber unit ranging data to the host unit; and

wherein the locator receiver is coupled to the serial radio frequency module through an interface that provides bidirectional access to the Ethernet pipe.

11. The remote unit of claim 10, wherein the digital radio frequency signal is a baseband digital radio frequency signal.

12. The remote unit of claim 10, wherein the digital radio frequency signal is a downconverted intermediate frequency (IF) digital radio frequency signal.

13. The remote unit of claim 10, the serial radio frequency module further comprising an interface for receiving the IP formatted data from the locator receiver.

14. The remote unit of claim 13, wherein the interface for receiving the IP formatted data from the locator receiver comprises an eight-position eight-contact modular plug.

15. A host unit for a digital distributed antenna system, the host unit comprising:

a serial radio frequency module receiving a plurality of serial streams from a plurality of remote units coupled to the serial radio frequency module, each of the plurality of serial streams transporting digitized radio frequency samples, each of the plurality of serial streams comprising a bandwidth with a first partition for transporting a digital radio frequency signal and a second partition implementing an Ethernet pipe for transporting subscriber unit ranging data to the host unit, wherein the serial radio frequency module sums the plurality of serial streams to produce an output to a digital to analog radio frequency transceiver module for transport to a base transceiver station;

a locator receiver coupled to the serial radio frequency module and processing digitized radio frequency samples from a first remote unit of the plurality of remote units to generate subscriber unit ranging data for a selected subscriber unit in communication with the first remote unit from the digital radio frequency signal of a serial stream received from one of the plurality of remote units, wherein the locator receiver adjust the subscriber unit ranging data to compensate for a propagation delay time associated with the first remote unit;

wherein the locator receiver outputs the subscriber unit ranging data as Internet Protocol (IP) formatted data for routing to a subscriber locator center; and

wherein the locator receiver is coupled to the serial radio frequency module through an interface that provides bidirectional access to the Ethernet pipe.

16. The remote unit of claim 15, wherein the locator receiver outputs the subscriber unit ranging data to the serial radio frequency module as Internet Protocol (IP) formatted data.

17. The remote unit of claim 16, wherein the serial radio frequency module outputs the subscriber unit ranging data to the base transceiver station via an Ethernet pipe.

18. The remote unit of claim 15, wherein the locator receiver receives a downconverted intermediate frequency (IF) digital radio frequency signal from the serial radio frequency module.

19. The remote unit of claim 15, wherein the locator receiver receives a baseband digital radio frequency signal from the serial radio frequency module.