Point-to-multipoint digital radio frequency transport

• US 20040132474A1
• Filed: 12/19/2003
• Published: 07/08/2004
• Est. Priority Date: 07/19/2000
• Status: Active Grant

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Wala, Philip M.
• Granted Patent: US 7,639,982 B2
• Time in Patent Office: Days
• US Class Current: 455/517
• CPC Class Codes: H03M 7/4006 Conversion to or from arithmetic code
• 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: H04B 3/02 Details
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04L 51/04 Real-time or near real-time messaging, e.g. instant messaging [IM]
• CPC Class Codes: H04L 51/48 Message addressing, e.g. address format or anonymous messages, aliases
• CPC Class Codes: H04L 51/58 Message adaptation for wireless communication
• CPC Class Codes: H04L 65/1016 IP multimedia subsystem [IMS]
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04N 19/109 among a plurality of temporal predictive coding modes
• CPC Class Codes: H04N 19/139 Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability
• CPC Class Codes: H04N 19/625 using discrete cosine transform [DCT]
• CPC Class Codes: H04N 19/91 Entropy coding, e.g. variable length coding [VLC] or arithmetic coding
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 2011/0047 Broadcast; Multicast
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 4/12 Messaging; Mailboxes; Announcements
• CPC Class Codes: H04W 4/14 Short messaging services, e.g. short message services [SMS] or unstructured supplementary service data [USSD]
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 88/08 : Access point devices
• CPC Class Codes: H04W 88/085 : Access point devices with remote components
• CPC Class Codes: Y10S 370/906 : Fiber data distribution interface, FDDI
• CPC Class Codes: Y10S 370/907 : Synchronous optical network, SONET

Abstract

A digital radio frequency transport system that performs bi-directional simultaneous digital radio frequency distribution is provided. The transport system includes a digital host unit and at least two digital remote units coupled to the digital host unit. The bi-directional simultaneous digital radio frequency distribution is performed between the digital host unit and the at least two digital remote units.

Claims

1. A digital radio frequency transport system, comprising:

a digital host unit; and

at least two digital remote units coupled to the digital host unit, wherein the digital host unit includes shared circuitry that performs bi-directional simultaneous digital radio frequency distribution between the digital host unit and the at least two digital remote units.

2. The system of claim 1, further comprising a wireless interface device coupled to the digital host unit.

3. The system of claim 2, wherein the wireless interface device comprises a base station that couples directly to the digital host unit via coaxial cables.

4. The system of claim 2, wherein the wireless interface device comprises a base station that wirelessly connects to the digital host unit via bi-directional amplifier that is coupled to an antenna.

5. The system of claim 1, wherein the at least two digital remote units each include a main radio frequency antenna which transmits and receives radio frequency signals.

6. The system of claim 1, wherein the digital host unit includes a radio frequency to digital converter that converts a main radio frequency signal to a digitized radio frequency signal.

7. The system of claim 6, wherein the digital host unit further includes a multiplexer which splits the digitized radio frequency signal into at least two digital signals for optical transmission to the at least two digital remote units.

8. The system of claim 1, wherein the digital host unit includes local oscillators coupled to a reference oscillator for synchronization of the radio frequency signal in the forward direction and in the reverse direction.

9. The system of claim 1, wherein the digital host unit is coupled to each of the at least two digital remote units by a multimode fiber pair.

10. The system of claim 7, wherein the digital host unit further comprises an alarm/control interface circuit coupled to the multiplexer.

11. The system of claim 1, further comprising a digital expansion unit coupled to the digital host unit, wherein the digital expansion unit contains circuitry that performs bi-directional simultaneous digital radio frequency distribution between the digital host unit and the digital remote unit.

12. The system of claim 11, wherein the digital expansion unit is coupled to the digital host unit by a multimode fiber pair.

13. The system of claim 11, wherein the digital expansion unit is coupled to the digital host unit by single mode fiber.

14. A digital radio frequency transport system, comprising:

a digital host unit;

at least one digital expansion unit coupled to the digital host unit; and

at least two digital remote units, each coupled to one of the digital host unit and the digital expansion unit, wherein the digital host unit includes shared circuitry that performs bi-directional simultaneous digital radio frequency distribution between the digital host unit and the at least two digital remote units.

15. The system of claim 14, further comprising a wireless interface device coupled to the digital host unit.

16. The system of claim 15, wherein the wireless interface device comprises a base station that couples directly to the digital host unit via coaxial cables.

17. The system of claim 15, wherein the wireless interface device comprises a base station that wirelessly connects to the digital host unit via a bi-directional amplifier that is coupled to an antenna.

18. The system of claim 14, wherein at least one digital remote unit is to coupled the digital host unit.

19. The system of claim 14, wherein at least one digital remote unit is coupled to one of the at least two digital expansion units.

20. The system of claim 14, wherein the at least one digital expansion units are each coupled to the digital host unit via a multimode fiber pair.

21. The system of claim 14, wherein the at least one digital expansion unit is coupled to the digital host unit via a single mode fiber.

22. The system of claim 14, wherein the digital host unit includes a radio frequency to digital converter that converts a main radio frequency signal to a digitized radio frequency signal.

23. The system of claim 22, wherein the digital host unit further includes a multiplexer which splits the digitized radio frequency signal into at least two digital signals for optical transmission to the at least two digital remote units.

24. The system of claim 14, wherein the digital host unit includes local oscillators coupled to a reference oscillator for synchronization of the radio frequency signal in the forward direction and in the reverse direction.

25. A method of performing multipoint-to-point digital radio frequency transport, the method comprising:

receiving analog radio frequency signals at multiple digital remote units;

converting the analog radio frequency signals to digital radio frequency signals at each of the digital remote units;

optically transmitting the digital radio frequency signals from each of the digital remote units to a digital host unit;

receiving the multiple digital radio frequency signals at the digital host unit;

summing the multiple digital radio frequency signals together; and

converting the digital radio frequency signals back to analog radio frequency signals and transmitting the signals to a wireless interface device for further transmission to a switched telephone network.

26. The method of claim 25, wherein converting the analog radio frequency signals to digital radio frequency signals comprises amplifying the analog radio frequency signals.

27. The method of claim 25, wherein converting the analog radio frequency signals to digital radio frequency signals comprises synchronizing a reverse path local oscillator to a mater clock so as to reduce end-to-end frequency translation.

28. A method of performing point-to-multipoint digital radio frequency transport, the method comprising:

receiving radio frequency signals at a digital host unit;

converting the radio frequency signals to a digitized radio frequency spectrum;

optically transmitting the digitized radio frequency spectrum to a plurality of digital remote units;

receiving the digitized radio frequency spectrum at the plurality of digital remote units;

converting the digitized radio frequency spectrum to analog radio frequency signals; and

transmitting the analog radio frequency signals via a main radio frequency antenna at each of the plurality of digital remote units.

29. The method of claim 28, wherein converting the radio frequency signals to a digitized radio frequency spectrum comprises amplifying the radio frequency signals.

30. The method of claim 28, wherein converting the radio frequency signals to a digitized radio frequency spectrum digital radio frequency signals comprises synchronizing a forward path local oscillator to a reference oscillator so as to reduce end-to-end frequency translation.

31. The method of claim 28, wherein converting the digitized radio frequency spectrum to analog radio frequency signals comprises amplifying the analog radio frequency signals.

32. The method of claim 28, wherein converting the digitized radio frequency spectrum to analog radio frequency signals comprises synchronizing a forward path local oscillator to a reference oscillator so as to reduce end-to-end frequency translation.

33. A method of performing point-to-multipoint digital radio frequency transport, the method comprising:

receiving radio frequency signals at a digital host unit;

converting the radio frequency signals to a digitized radio frequency spectrum;

optically transmitting a first digitized radio frequency spectrum to a first plurality of digital remote units and at least one digital expansion unit;

receiving the digitized radio frequency spectrum at the first plurality of digital remote units;

converting the digitized radio frequency spectrum to analog radio frequency signals at each of the first plurality of digital remote units;

receiving the digital radio frequency signals at the at least one digital expansion unit;

optically transmitting a second digitized radio frequency spectrum to a second plurality of digital remote units;

receiving the second digitized radio frequency spectrum at the second plurality of digital remote units;

converting the second digitized radio frequency spectrum to analog radio frequency signals at each of the second plurality of digital remote units; and

transmitting the analog radio frequency signals via a main radio frequency antenna at each of the first and second plurality of digital remote units.

34. A digital radio frequency transport system, comprising:

a digital host unit; and

at least two digital remote units coupled to the digital host unit, wherein the at least two digital remote units each include;

a main radio frequency antenna;

a duplexer coupled to the main radio frequency antenna which receives radio frequency signals in the reverse path and transmits radio frequency signals in the forward path;

a radio frequency to digital converter coupled to the duplexer in the reverse path;

a digital to radio frequency converter coupled to the duplexer in the forward path;

a multiplexer chip set coupled to the radio frequency to digital converter in the reverse path and the digital to radio frequency converter in the forward path;

an optical transmitter coupled to an output of the multiplexer chip set; and

an optical receiver coupled to an input of the multiplexer chip set;

wherein the digital host unit includes shared circuitry that performs bi-directional simultaneous digital radio frequency distribution between the digital host unit and the at least two digital remote units.

35. The system of claim 34, wherein the digital host unit includes an alarm/control interface circuit.

36. A digital radio frequency transport system, comprising:

a digital host unit, wherein the digital host unit includes a channel summer;

at least one digital expansion unit coupled to the digital host unit; and

at least two digital remote units coupled to the digital host unit, wherein the digital host unit includes shared circuitry that performs bi-directional simultaneous digital radio frequency distribution between the digital host unit and the at least two digital remote units.