Method and apparatus for providing location services for a distributed network

• US 8,081,923 B1
• Filed: 12/17/2007
• Issued: 12/20/2011
• Est. Priority Date: 02/13/2007
• Status: Active Grant

• Current Assignee: ExteNet Systems, Inc.
• Original Assignee: ExteNet Systems, Inc.
• Inventors: Larsen, Tormod, Rivas, Antonio
• Primary Examiner(s): Nguyen, Tu X
• Application Number:
  US11/958,100
• Time in Patent Office: 1,464 Days
• Field of Search: 455/404.2, 455/404.1, 455/67.16, 455/423, 455/7, 455/10, 455/16, 455/18, 455/502, 455/67.11, 455/456.5, 455/561, 455/562.1, 455/456.1, 455/14
• US Class Current: 455/18
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• 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: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• 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

A method and system for normalizing various simulcasting nodes within a distributed antenna system (DAS) simulcast sector uses the simulcast sector'"'"'s known fiber delays, the distance between the nodes, and its corresponding RF delays. The methodology includes adding calculated delays to the known fiber delays to normalize each node'"'"'s delay. Each normalized node delay value is equal to the value of the fiber delay of the furthest node plus the respective RF delay distance from that node.

Claims

1. A processing system for normalizing simulcast antenna nodes of a distributed antenna system (DAS) within a DAS simulcast sector, the processing system comprising:

a processor communicatively connected to a distributed antenna system in which each given simulcast antenna node of a plurality of simulcast antenna nodes has a respective fiber delay corresponding to a propagation delay on a respective, distinct communication fiber connecting the given simulcast antenna node to a base station hotel (BSH);

a memory communicatively connected to the processor and adapted to store a computer program that when executed by the processor causes the system to carry out functions comprising;

selecting a reference simulcast antenna node within the DAS simulcast sector from among the plurality of simulcast antenna nodes;

calculating a respective radio frequency (RF) delay for each simulcast antenna node of the plurality of simulcast antenna nodes;

calculating a respective fiber delay difference of between the respective fiber delay of each simulcast antenna node and the respective fiber delay of the reference simulcast antenna node;

computing a respective differential delay for each simulcast antenna node by adding the respective RF delay and the respective fiber delay difference corresponding to each simulcast antenna node; and

calculate the calculating a respective total delay for each simulcast antenna node by adding the result of the fourth respective differential delay to the respective fiber delay of each simulcast antenna node.

2. The processing system of claim 1, wherein calculating the respective RF delay for each simulcast antenna node comprises calculating a straight line distance between the simulcast antenna node and the reference simulcast antenna node.

3. The processing system of claim 1, wherein calculating the respective fiber delay difference comprises determining the respective fiber delay of each given simulcast antenna node of the plurality of simulcast antenna nodes from optical time domain reflector (OTDR) measurements of the given simulcast antenna node from the BSH.

4. The processing system of claim 1, wherein the functions further comprise using the respective total delay of each simulcast antenna node to calculate at least one of a transmission delay, a reception delay, and a maximum differential delay of the DAS simulcast sector.

5. The processing system of claim 4, wherein the functions further comprise synchronizing the DAS simulcast sector to at least one of (1) a CDMA network, (2) a GSM based cellular network, and (3) a TDMA based cellular network, based on the calculated at least one of a transmission delay, a reception delay, and a maximum differential delay of the DAS simulcast sector.

6. The processing system of claim 1, wherein the DAS simulcast sector is connected to at least one of an 802.11 wireless data network and an 802.16 wireless data network.

7. A method of normalizing a plurality of simulcast antenna nodes of a distributed antenna system (DAS) within a DAS simulcast sector, the method comprising:

determining a respective fiber delay for each given simulcast antenna node of the plurality of simulcast antenna nodes by measuring a propagation delay on a respective, distinct communication fiber connecting the given simulcast antenna node to a base station hotel (BSH);

selecting a reference simulcast antenna node within the simulcast sector from among the plurality of simulcast antenna nodes;

calculating a respective radio frequency (RF) delay for each simulcast antenna node of the plurality of simulcast antenna nodes;

calculating a respective fiber delay difference between the respective fiber delay of each simulcast antenna node and the respective fiber delay of the reference simulcast antenna node;

computing a respective differential delay for each simulcast antenna node by adding the respective RF delay and the respective fiber delay difference corresponding to each simulcast antenna node; and

calculating a respective total delay for each simulcast antenna node by adding the respective differential delay to the respective fiber delay of each simulcast antenna node.

8. The method of claim 7, wherein calculating respective radio frequency (RF) delay for each simulcast antenna node comprises calculating a straight line distance between the simulcast antenna node and the reference simulcast antenna node.

9. The method of claim 7, wherein measuring the propagation delay on the respective, distinct communication fiber comprises using domain reflector (OTDR) to measure the given simulcast antenna node from the BSH.

10. The method of claim 7, further comprising using the respective total delay of each simulcast antenna node to calculate at least one of a transmission delay, a reception delay and a maximum differential delay of the DAS simulcast sector.

11. The method of claim 10, further comprising synchronizing the DAS simulcast sector to at least one of (1) a CDMA network, (2) a GSM based cellular network, and (3) a TDMA based cellular network, based on the calculated at least one of a transmission delay, a reception delay, and a maximum differential delay of the DAS simulcast sector.

12. The method of claim 7, wherein the DAS simulcast sector is connected to at least one of an 802.11 wireless data network and an 802.16 wireless data network.

13. A non-transitory computer readable medium having instructions stored thereon that, when executed by a processor of a processing system, cause the processing system to carry out functions comprising:

determining a respective fiber delay for each given simulcast antenna node of a plurality of simulcast nodes of a distributed antenna system (DAS) within a DAS simulcast sector, wherein the processing system is configured to communicate with the DAS, and wherein the respective fiber delay corresponds to a propagation delay on a respective, distinct communication fiber connecting the given simulcast antenna node to a base station hotel (BSH);

selecting a reference simulcast antenna node within the DAS simulcast sector from among the plurality of simulcast antenna nodes;

calculating a respective radio frequency (RF) delay for each simulcast antenna node of the plurality of simulcast antenna nodes;

calculating a respective fiber delay difference between the respective fiber delay of each simulcast antenna node and the respective fiber delay of the reference simulcast antenna node;

computing a respective differential delay for each simulcast antenna node by adding the respective RF delay and the respective fiber delay difference corresponding to each simulcast antenna node; and

calculating a respective total delay for each of the simulcast antenna node by adding the respective differential delay to the respective fiber delay of each simulcast antenna node.

14. The non-transitory computer readable medium of claim 13, wherein the calculating the respective RF delay for each simulcast antenna node comprises calculating a straight line distance between the simulcast antenna node and the reference simulcast antenna node.

15. The non-transitory computer readable medium of claim 13, wherein calculating the respective fiber delay difference comprises determining the respective fiber delay of each given simulcast antenna node of the plurality of simulcast nodes from optical time domain reflector (OTDR) measurements of the given simulcast antenna node from the BSH.

16. The non-transitory computer readable medium of claim 13, wherein the functions further comprise using the respective total delay of each simulcast antenna node to calculate at least one of a transmission delay, a reception delay, and a maximum differential delay of the DAS simulcast sector.

17. The non-transitory computer readable medium of claim 16, wherein the functions further comprise synchronizing the DAS simulcast sector to at least one of (1) a CDMA network, (2) a GSM based cellular network, and (3) a TDMA based cellular network, based on the calculated at least one of a transmission delay, a reception delay, and a maximum differential delay of the DAS simulcast sector.

18. The non-transitory computer readable medium of claim 13, wherein the DAS simulcast sector is configured to be connected to at least one of an 802.11 wireless data network and an 802.16 wireless data network.