Implementation of a fiber distributed antenna system network while maintaining synchronization

• US 9,307,506 B1
• Filed: 09/09/2014
• Issued: 04/05/2016
• Est. Priority Date: 09/09/2014
• Status: Active Grant

• Current Assignee: T-Mobile Innovations LLC (Deutsche Telekom AG)
• Original Assignee: Sprint Communications Company LP (Deutsche Telekom AG)
• Inventors: Rausch, Walter Fred, Kelly, Ivy Yvonne
• Primary Examiner(s): Bello, Agustin
• Application Number:
  US14/481,449
• Time in Patent Office: 574 Days
• Field of Search: 398115-118
• US Class Current: 1/1
• CPC Class Codes: H04B 10/0793 Network aspects, e.g. central monitoring of transmission parameters
• CPC Class Codes: H04B 10/25753 Distribution optical network, e.g. between a base station and a plurality of remote units
• CPC Class Codes: H04B 10/25754 Star network topology
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 56/006 using known positions of transmitter and receiver
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

Systems for synchronizing transmission through the introduction of a specific additional delay in a wireless telecommunications network are provided. RF transmission delays are adjusted for a distributed antenna system (DAS) that must maintain synchronization with RF transmissions in a macro cellular network. Delays are introduced at each DAS node using a delay panel or a measurement procedure to synchronize the transmission of the DAS with the macro cellular network.

Claims

1. A system for synchronizing transmission through the introduction of a specific additional delay in a wireless telecommunications network, comprising:

at least a distributed antenna system (DAS) connected to a central communications hub site, wherein the central communications hub site is part of a macro cellular network;

the DAS comprising one or more DAS nodes distributed in an area to transmit and receive radio frequency (RF) signals, wherein each of the one or more DAS nodes comprises at least one antenna to facilitate RF transmission, and wherein each of the one or more DAS nodes is located at a same distance or a different distance to another of the one or more DAS nodes from the central communications hub site;

the one or more DAS nodes encounter a delay in transmission of the RF signals because of their respective one or more distances from the central communications hub site, wherein each of the one or more DAS nodes encounter an amount of the delay in proportion to its distance from the central communications hub site; and

each of the one or more DAS nodes further delays transmission to synchronize with transmissions within the macro cellular network, wherein each of the one or more DAS nodes transmits RF signals at a same time as RF signals in the macro cellular network to avoid interference.

2. The system of claim 1, wherein a DAS node includes at least one of an antenna, amplifier, remote radio head, signal converter, and a power supply.

3. The system of claim 2, wherein the central communications hub site is a base station.

4. The system of claim 2, wherein the macro cellular network includes wireless technologies such as Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Evolution-Data Optimized (EV-DO), Enhanced Data Rates for GSM Evolution (EDGE), Universal Mobile Telecommunications System (UMTS), Digital Enhanced Cordless Telecommunications (DECT), Integrated Digital Enhanced Network (iDEN), High Speed Packet Access (HSPA), Worldwide Interoperability for Microwave Access (WiMAX), Long-Term Evolution (LTE), or LTE Advanced.

5. The system of claim 2, wherein each of the one or more DAS nodes is connected to the central communications hub site over a fiber optic cable.

6. The system of claim 5, wherein the one or more DAS nodes are connected to the central communications hub site with fiber optic cables in a hub and spoke configuration.

7. The system of claim 5, wherein the one or more DAS nodes are connected to the central communications hub site with fiber optic cables in a daisy chain configuration, wherein one of the one or more DAS nodes connects to the central communications hub site through another of the one or more DAS nodes.

8. A system for synchronizing transmission through the introduction of a specific additional delay in a wireless telecommunications network, comprising:

a base station operates located in a macro cellular network and receives timing synchronization from a global positioning system (GPS) source;

the base station connected to a distributed antenna system (DAS), wherein the DAS does not receive timing synchronization from the GPS source;

the DAS comprising one or more DAS nodes distributed in an area to transmit and receive radio frequency (RF) signals, wherein each of the one or more DAS nodes comprises an antenna to facilitate RF transmission and comprises an RF delay device to facilitate transmission delay of an RF signal, and wherein each of the one or more DAS nodes is located at a same distance or a different distance to another of the one or more DAS nodes from the base station;

each of the one or more DAS nodes encounters a transmission delay due to their respective distance from the base station and lack of timing from the GPS source; and

the RF delay device at each of the one or more DAS nodes delays a transmission of the RF signal such that the RF signal is transmitted at a same time as RF signals within the macro cellular network to avoid interference.

9. The system of claim 8, wherein the base station delays transmission to the DAS such that a data transmission from the DAS is at least one frame behind the data transmission in the macro cellular network, wherein the data transmission from the one or more DAS nodes are at least one frame behind the data transmission in the macro cellular network.

10. The system of claim 8, wherein a DAS node includes at least one of an antenna, amplifier, remote radio head, signal converter, and a power supply.

11. The system of claim 10, further comprising the DAS including a DAS hub with the one or more DAS nodes, wherein the DAS hub connects the one or more DAS nodes with the base station.

12. The system of claim 10, wherein the macro cellular network includes wireless technologies such as Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Evolution-Data Optimized (EV-DO), Enhanced Data Rates for GSM Evolution (EDGE), Universal Mobile Telecommunications System (UMTS), Digital Enhanced Cordless Telecommunications (DECT), Integrated Digital Enhanced Network (iDEN), High Speed Packet Access (HSPA), Worldwide Interoperability for Microwave Access (WiMAX), Long-Term Evolution (LTE), or LTE Advanced.

13. The system of claim 10, wherein each of the one or more DAS nodes is connected to the base station over a fiber optic cable.

14. The system of claim 13, wherein the one or more DAS nodes are connected to the base station with fiber optic cables in a hub and spoke configuration.

15. The system of claim 13, wherein the one or more DAS nodes are connected to the base station with fiber optic cables in a daisy chain configuration, wherein one of the one or more DAS nodes connects to the base station through another of the one or more DAS nodes.

16. A system for reducing transmission interference between wireless devices in a wireless telecommunications network, comprising:

a central communications hub site operable in a macro cellular network and receives timing synchronization from a global positioning system (GPS) source;

one or more distributed antenna system (DAS) nodes connected to the central communications hub site in the macro cellular network, wherein the one or more DAS nodes do not receive timing synchronization from the GPS source, wherein each of the one or more DAS nodes comprises an antenna to facilitate RF transmission, and wherein each of the one or more DAS nodes is located at a same distance or a different distance to another of the one of more DAS nodes from the central communications hub site;

the central communications hub site sends a signal that instructs a member of the one or more DAS nodes to go into loop back mode, and subsequently, the central communications hub site measures an amount of delay at the member of the one or more DAS nodes, wherein the central communications hub site communicates the amount of delay to the member of the one or more DAS nodes;

the member of the one or more DAS nodes comes out of loop back mode and goes into normal mode after a measurement of the amount of delay;

based on the amount of delay, the member of the one or more DAS nodes sets a start time for transmission based on the amount of delay such that an RF signal is transmitted at a same time as RF signals in the macro cellular network to avoid interference.

17. The system of claim 16, wherein a DAS node includes at least one of an antenna, amplifier, remote radio head, signal converter, and a power supply.

18. The system of claim 17, wherein the central communications hub site is a base station.

19. The system of claim 17, further comprising a DAS hub inserted between the one or more DAS nodes and the central communications hub site, wherein the DAS hub connects the one or more DAS nodes with the central communications hub site.

20. The system of claim 17, wherein the macro cellular network includes wireless technologies such as Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Evolution-Data Optimized (EV-DO), Enhanced Data Rates for GSM Evolution (EDGE), Universal Mobile Telecommunications System (UMTS), Digital Enhanced Cordless Telecommunications (DECT), Integrated Digital Enhanced Network (iDEN), High Speed Packet Access (HSPA), Worldwide Interoperability for Microwave Access (WiMAX), Long-Term Evolution (LTE), and LTE Advanced.

21. The system of claim 17, wherein each of the one or more DAS nodes is connected to the central communications hub site over a fiber optic cable.

22. The system of claim 21, wherein the one or more DAS nodes are connected to the central communications hub site with fiber optic cables in a hub and spoke configuration.

23. The system of claim 21, wherein the one or more DAS nodes are connected to the central communications hub site with fiber optic cables in a daisy chain configuration, wherein one of the one or more DAS nodes connects to the central communications hub site through another of the one or more DAS nodes.