Systems and methods of transporting internal radio base station (RBS) interface information over a packet switched network

Patent metadata

Field	Value
Publication number	US-9608752-B2
Application number	US-201514746213-A
Country	US
Kind code	B2
Filing date	Jun 22, 2015
Priority date	May 15, 2015
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

Systems and methods of transporting internal radio base station (RBS) interface information over a packet network are presented. In one exemplary embodiment, in an interworking function (IWF) for communicating packets between a radio equipment (RE) and a radio equipment controller (REC) of a radio base station (RBS), a method may include receiving a packet sent from another IWF and having internal RBS interface information and residence time measurement (RTM) information that characterizes an asymmetry between processing times on links in different directions between the RE and the REC. Further, the method may include determining an asymmetry compensation that compensates for the asymmetry using the RTM information. Also, the method may include applying the asymmetry compensation to a timestamp of the internal RBS interface information to obtain an updated internal RBS interface information. In addition, the method may include transmitting the updated internal RBS interface information to one of the RE and the REC that is attached to the IWF.

First claim

What is claimed is:

1. A method performed by an interworking function (IWF) for communicating packets between a radio equipment (RE) and a radio equipment controller (REC) of a radio base station (RBS), comprising:
receiving a packet sent from another IWF and having internal RBS interface information and residence time measurement (RTM) information that characterizes an asymmetry between processing times on links in different directions between the RE and the REC;
determining an asymmetry compensation that compensates for the asymmetry using the RTM information; and
applying the asymmetry compensation to a timestamp of the internal RBS interface information to obtain an updated internal RBS interface information; and
transmitting the updated internal RBS interface information to one of the RE and the REC that is attached to the IWF.

2. The method of claim 1 , further comprising:
determining an RTM associated with the IWF processing the packet; and
updating the RTM information of the packet using the RTM associated with the IWF processing the packet.

3. The method of claim 1 , further comprising:
determining a packet delay variation (PDV) compensation that compensates a PDV of the packet using the RTM information of the packet, wherein the RTM information also characterizes the PDV of the packet on a link from the other IWF to the IWF;
applying the PDV compensation to a transmission time of the updated internal RBS interface information to obtain an updated transmission time; and
wherein transmitting includes transmitting the updated internal RBS interface information at the compensated transmission time to the one of the RE and the REC that is attached to the IWF.

4. The method of claim 1 , wherein the internal RBS interface information includes common public radio interface (CPRI) information.

5. The method of claim 1 , wherein the packet includes precision time protocol (PTP) information.

6. The method of claim 1 , wherein the packet includes an RTM header having the RTM information of the packet.

7. The method of claim 1 , wherein the packet is a pseudo-wire emulation packet.

8. The method of claim 1 , wherein the RTM information of the packet includes a forward accumulated RTM and a reverse accumulated RTM, or a difference between the forward accumulated RTM and the reverse accumulated RTM.

9. The method of claim 1 , wherein the IWF does not use a precision time protocol (PTP).

10. An interworking function (IWF) for communicating packets between a radio equipment (RE) and a radio equipment controller (REC) of a radio base station (RBS), comprising:
a first interface circuit configured to receive a packet sent from another IWF and having internal RBS interface information and a residence time measurement (RTM) information that characterizes an asymmetry between processing times on links in different directions between the RE and the REC;
a processor operationally coupled to the first interface and configured to:
determine the asymmetry compensation that compensates the asymmetry using the RTM information; and
apply the asymmetry compensation to a timestamp of the internal RBS interface information to obtain an updated internal RBS interface information; and

a second interface circuit operationally coupled to the processor and configured to transmit the updated internal RBS interface information to one of the RE and the REC that is attached to the IWF.

11. The IWF of claim 10 , wherein the processor is further configured to:
determine an RTM associated with the IWF processing the packet; and
update the RTM information of the packet using the RTM associated with the IWF processing the packet.

12. The IWF of claim 10 , wherein the processor is further configured to:
determine a packet delay variation (PDV) compensation that compensates a PDV of the packet using the RTM information of the packet, wherein the RTM information also characterizes the PDV of the packet on a link from the other IWF to the IWF; and
apply the PDV compensation to a transmission time of the updated internal RBS interface information to obtain a compensated transmission time; and
wherein the second interface circuit is further configured to transmit the updated internal RBS interface information at the compensated transmission time to the one of the RE and the REC that is attached to the IWF.

13. The IWF of claim 10 , wherein the RTM information of the packet includes a forward accumulated RTM and a reverse accumulated RTM, or a difference between the forward accumulated RTM and the reverse accumulated RTM.

14. The IWF of claim 10 , wherein the internal RBS interface information includes common public radio interface (CPRI) information.

15. The IWF of claim 10 , wherein the packet includes an RTM header having the RTM information.

16. A system for communicating packets between a radio equipment (RE) and a radio equipment controller (REC) of a radio base station (RBS), comprising:
a first interworking function (IWF) operationally coupled to the RE;
a second IWF operationally coupled between the first IWF and the REC;
wherein the first IWF is configured to:
receive a forward packet sent from the second IWF and having a forward internal RBS interface information and a forward residence time measurement (RTM) information that characterizes a forward packet delay variation (PDV) of the forward packet on a forward link;
determine a forward PDV compensation that compensates for the forward PDV using the forward RTM information;
apply the forward PDV compensation to a forward transmission time of the forward internal RBS interface information to obtain a compensated forward transmission time; and
transmit, to the RE, the updated forward internal RBS interface information at the compensated forward transmission time; and

a second IWF operationally coupled between the first IWF and the REC, wherein the second IWF is configured to:
receive a reverse packet sent from the first IWF and having a reverse internal RBS interface information and a reverse RTM information that characterizes a reverse PDV of the reverse packet on a reverse link;
determine a reverse PDV compensation that compensates for the reverse PDV using the reverse RTM information;
apply the reverse PDV compensation to a reverse transmission time of the reverse internal RBS interface information to obtain a compensated reverse transmission time; and
transmit, to the REC, the updated reverse internal RBS interface information at the compensated reverse transmission time.

17. The system of claim 16 , wherein the first IWF is further configured to:
determine an RTM associated with the first IWF processing the forward packet;
update the forward RTM information of the forward packet using the RTM associated with the first IWF processing the forward packet;
determine an RTM associated with the first IWF processing the reverse packet; and
update the reverse RTM information of the reverse packet using the RTM associated with the first IWF processing the reverse packet.

18. The system of claim 16 , wherein the second IWF is further configured to:
determine an RTM associated with the second IWF processing the forward packet; and
update the forward RTM information of the forward packet using the RTM associated with the second IWF processing the forward packet;
determine an RTM associated with the second IWF processing the reverse packet; and
update the reverse RTM information of the reverse packet using the RTM associated with the second IWF processing the reverse packet.

Assignees

• Ericsson Telefon Ab L M
• ERICSSON TELEFON AB L M (publ)

Inventors

• Ruffini Stefano
• Mirsky Gregory
• Gray Eric Ward

Classifications

• H04J3/0667 Primary

  Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays (arrangements for monitoring round trip delays in packet switching networks H04L43/0864) · CPC title

• H04J3/0694

  Synchronisation in a TDMA node, e.g. TTP · CPC title

• H04J3/0658

  Clock or time synchronisation among packet nodes · CPC title

• H04W56/005

  compensating for timing error by adjustment in the receiver · CPC title

• H04J3/0647

  Synchronisation among TDM nodes · CPC title