# US 9,438,431 B2 · Method of transmitting traffic in a communications network and communications network apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,438,431 B2 - Document ID: US9438431B2 - Status: Granted - Kind: B2 - Application number: 13/221,283 - Filed: 2011-08-30 - Published: 2012-03-08 - Granted: 2016-09-06 - Earliest claimed: 2010-09-02 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Ghani Abdul Muttalib Abbas; Philip Andrew Arnold - Inventors: Ghani Abdul Muttalib Abbas; Philip Andrew Arnold - Web page: https://patentgrep.com/patent/US9438431B2 ## CPC - H04L 12/12: Arrangements for remote connection or disconnection of substations or of equipment thereof - H04L 5/1446: {of transmission speed} - H04L 25/0262: {Arrangements for detecting the data rate of an incoming signal} - H04L 47/25: with rate being modified by the source upon detecting a change of network conditions - H04L 49/90: Buffering arrangements - H04L 47/30: in combination with information about buffer occupancy at either end or at transit nodes - Y02D 30/50: in wire-line communication networks, e.g. low power modes or reduced link rate - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract A method 10 of transmitting traffic in a communications network. The method comprises receiving client signal having a client bit rate and comprising traffic to be transmitted 12 and monitoring an indicator indicative of said client bit rate 12. The method further comprises setting a transmission bit rate at which to transmit the traffic 16. The transmission bit rate is set in dependence on said client bit rate. The method further comprises generating and transmitting a control signal arranged to cause a transmission apparatus to transmit the traffic at the transmission bit rate 18. ## Claims ### Claim 1 A method of transmitting traffic in a communications network, the method comprising: receiving a client signal in a buffer, the client signal having a client bit rate and comprising traffic to be transmitted by a transmission element; monitoring an indicator indicative of said client bit rate, wherein the indicator indicative of said client bit rate corresponds to a fill rate or fill level of the buffer; setting a transmission bit rate of the transmission element at which to transmit the traffic, the transmission bit rate being set in dependence on said client bit rate determined from monitoring the indicator; wherein the transmission bit rate of the transmission element is reduced in response to receiving a said client bit rate which is less than a maximum transmission bit rate capability of the transmission element; and varying a clock rate to cause a transmission apparatus to transmit the traffic at the transmission bit rate. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein the transmission bit rate set by varying the clock rate comprises determining a divide ratio for a master bit rate in dependence on said client bit rate and generating and transmitting a control signal that comprises a clock signal generated by receiving a master clock signal at the master bit rate and dividing the master clock signal by the divide ratio. ### Claim 3 (depends on 1) The method as claimed in claim 1, wherein the method comprises: receiving a first client signal having a first client bit rate and comprising first traffic to be transmitted and subsequently receiving a second client signal having a second client bit rate and comprising second traffic to be transmitted; setting a first transmission bit rate in dependence on the first client bit rate and setting a second transmission bit rate in dependence on the second client bit rate; generating and transmitting a first control signal arranged to cause a framer to frame the first traffic into one or more first frames at the first transmission bit rate and a second control signal arranged to cause the framer to frame the second traffic into one or more subsequent frames at the second transmission bit rate, and, where the second transmission bit rate is different to the first transmission bit rate, the second control signal is further arranged to cause the framer to implement the change from the first transmission bit rate to the second transmission bit rate at a frame boundary. ### Claim 4 (depends on 3) The method as claimed in claim 3, wherein the first control signal is arranged to cause the framer to frame a part of the first traffic in a payload of said first frame and to cause the framer to provide information indicative of the second transmission bit rate in an overhead of said first frame. ### Claim 5 (depends on 4) The method as claimed in claim 4, wherein said first frame comprises an optical transport network frame. ### Claim 6 (depends on 1) The method as claimed in claim 1, wherein the method further comprises receiving transmitted traffic at receiver apparatus and determining whether a value for the transmission bit rate is available, and, if a value for the transmission bit rate is not available, causing a further transmission apparatus to generate and transmit a recovery signal arranged to cause the transmission apparatus to transmit traffic at a default transmission bit rate. ### Claim 7 (depends on 6) The method as claimed in claim 6, wherein the recovery signal is arranged to cause a remote transmission apparatus to re-transmit the traffic on a transport signal at the default transmission bit rate. ### Claim 8 (depends on 6) The method as claimed in claim 6, wherein the recovery signal is transmitted at a pre-determined recovery signal transmission bit rate and the method comprises framing the recovery signal in a payload of a frame and providing a recovery signal identifier in an overhead of the frame. ### Claim 9 (depends on 1) The method as claimed in claim 1, wherein the indicator comprises a client bit rate signal. ### Claim 10 A communications network transmission element comprising: an input arranged to receive a client signal having a client bit rate and comprising traffic to be transmitted by a transmission element; client signal monitoring apparatus arranged to monitor an indicator indicative of said client bit rate, wherein the client signal monitoring apparatus comprises a buffer arranged to receive the client signal and the indicator indicative of said client bit rate corresponds to a fill rate or fill level of the buffer; transmission bit rate control apparatus arranged to set a transmission bit rate of the transmission element at which to transmit the received traffic, the transmission bit rate being set in dependence on said client bit rate determined from monitoring the indicator, wherein: the transmission bit rate of the transmission element is reduced in response to receiving a said client bit rate which is less than a maximum transmission bit rate capability of the transmission element, and the transmission bit rate control apparatus being further arranged to vary a clock rate arranged to cause a transmission apparatus to transmit the traffic at the transmission bit rate; and the transmission apparatus arranged to receive the clock rate and to generate and transmit a transport signal carrying the traffic. ### Claim 11 (depends on 10) The communications network transmission element as claimed in claim 10, wherein to vary the clock rate, the transmission bit rate control apparatus comprises a controller arranged to determine a divide ratio in dependence on said client bit rate, a clock arranged to generate a master clock signal having a master bit rate, and a divider arranged to receive the divide ratio and to divide the master clock signal at the divide ratio to form a control signal. ### Claim 12 (depends on 10) The communications network transmission element as claimed in claim 10 wherein the input is arranged to receive a first client signal having a first client bit rate and comprising first traffic to be transmitted and to subsequently receive a second client signal having a second client bit rate and comprising second traffic to be transmitted, and the transmission apparatus comprises a framer, and wherein the transmission bit rate control apparatus is arranged to set a first transmission bit rate in dependence on the first client bit rate at which to transmit the first traffic and to set a second transmission bit rate in dependence on the second client bit rate at which to transmit the second traffic, and the transmission bit rate control apparatus is further arranged to generate and transmit a first control signal arranged to cause the framer to frame the first traffic into one or more first frames at the first transmission bit rate and a second control signal arranged to cause the framer to frame the second traffic into one or more subsequent frames at the second transmission bit rate, and, where the second transmission bit rate is different to the first transmission bit rate, the second control signal is further arranged to cause the framer to implement the change from the first transmission bit rate to the second transmission bit rate at a frame boundary. ### Claim 13 (depends on 12) The communications network transmission element as claimed in claim 12, wherein the first control signal is arranged to cause the framer to frame a part of the first traffic in a payload of a said first frame and to cause the framer to provide information indicative of the second transmission bit rate in an overhead of the first frame. ### Claim 14 (depends on 12) The communications network transmission element as claimed in claim 12, wherein said first frame comprises an optical transport network frame. ### Claim 15 (depends on 10) The communications network transmission element as claimed in claim 10, wherein the client signal monitoring apparatus is arranged to monitor a client bit rate signal indicative of the client bit rate. ### Claim 16 (depends on 10) The communications network transmission element as claimed claim 10, wherein the communications network transmission element further comprises a receiver arranged to receive a recovery signal arranged to cause the transmission apparatus to transmit a transport signal carrying traffic at a default bit rate. ### Claim 17 A communications network comprising: a communication network transmission element including: an input arranged to receive a client signal in a buffer, the client signal having a client bit rate and comprising traffic to be transmitted by a transmission element; client signal monitoring apparatus arranged to monitor an indicator indicative of said client bit rate, wherein the indicator indicative of said client bit rate corresponds to a fill rate or fill level of the buffer; transmission bit rate control apparatus arranged to: set a transmission bit rate of the transmission element at which to transmit the received traffic, the transmission bit rate being set in dependence on said client bit rate determined from monitoring the indicator, wherein the transmission bit rate of the transmission element is reduced in response to receiving a said client bit rate which is less than a maximum transmission bit rate capability of the transmission element; vary a clock rate arranged to cause a transmission apparatus to transmit the traffic at the transmission bit rate; and receive the clock rate and transmit a transport signal carrying the traffic; and a communication network element including: an input arranged to receive a transport signal carrying traffic and having a transmission bit rate: transport signal interrogation apparatus arranged to determine whether a value for the transmission bit rate is available and being further arranged to, if a value for the transmission bit rate is not available, generate a recovery signal arranged to cause a remote transmission apparatus to transmit a transport signal carrying traffic at a default transmission bit rate; and local transmission apparatus arranged to transmit the recovery signal. ### Claim 18 A method of framing traffic for transmission in a communications network, the method comprising: receiving a first client signal having a first client bit rate and comprising first traffic to be transmitted at a first transmission bit rate by a transmission element; receiving a second client signal in a buffer, the second client signal having a second client bit rate and comprising second traffic to be transmitted at a second transmission bit rate by the transmission element, the second transmission bit rate being set in dependence on said second client bit rate determined from monitoring a fill rate or fill level of the buffer, wherein the second transmission bit rate of the transmission element is reduced in response to the second client bit rate being less than a maximum transmission bit rate capability of the transmission element; generating and transmitting a control signal arranged to cause a framer to frame a part of the first traffic in a payload of a frame and to cause the framer to provide information indicative of the second transmission bit rate in an overhead of the frame; varying a clock rate to cause the first traffic to transmit at the first transmission bit rate and the second traffic to transmit at the second transmission bit rate. ### Claim 19 (depends on 18) The method as claimed in claim 18, wherein the frame comprises an optical transport network frame.