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US6556573B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Synchronization of ATM-based network system using variable bit rate ATM adaptation layer protocols

Assignee: Nokia Oyj
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Filing: 1998-06-05
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Granted: 2003-04-29
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Expires: 2018-06-05
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Abstract

Abstract A system and method for synchronizing variable bit rate traffic between a source and destination in an Asynchronous Transfer Mode (ATM) network. The method includes designating a variable bit rate ATM Adaptation Layer (AAL) protocol to define ATM cell traffic flow from the source to the destination. A synchronous residual timestamp (SRTS) value indicative of the timing of a source clocking function is encoded and transmitted with an ATM cell using a variable bit rate AAL, such as AAL2 or AAL5. The ATM cells and associated SRTS values are received and decoded at the destination ATM interface, and the destination clock is synchronized with the source clock by modifying the destination clock according to the SRTS values.

Inventors

  • 👤 Topi Johannes Kaaresoja

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 12:26
CPC Classifications
H; H04; H04J; H04J3/00; H04J3/02; H04J3/06; H04J3/062; H04J3/0632; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04Q11/0478; H04L; H04L12/00; H04L12/54; H04L12/56; H04L12/5601; H04L2012/5672; H04L2012/5674

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 196 words
A method for synchronizing variable bit rate traffic between a source and destination in an Asynchronous Transfer Mode (ATM) network, comprising: designating a variable bit rate ATM Adaptation Layer (AAL) protocol, AAL5, to define ATM cell traffic flow from the source to the destination; encoding a synchronous residual timestamp (SRTS) value indicative of the timing of a source clocking function using one or more sequence numbers and one or more portions of the SRTS value; creating an SRTS field in an AAL5 Common Part Convergence Sublayer Protocol Data Unit (CPCS-PDU) trailer to occupy at least a portion of the SRTS value; creating a sequence number (SN) field in the AAL5 CPCS-PDU trailer to occupy a sequence number corresponding to a sequence and completion status of segmented portions of the SRTS value; transmitting the CPCS-PDU, including the sequence number and the segmented portion of the SRTS value from the CPCS-PDU trailer, using the AAL5 protocol; receiving the ATM cells and corresponding SRTS values at the destination; decoding the SRTS value for use at the destination; and synchronizing a destination clocking function with the source clocking function by modifying the destination clocking function according to the SRTS values.
Claim 2
Independent Claim 196 words
A method for synchronizing variable bit rate traffic between a source and destination in an Asynchronous Transfer Mode (ATM) network, comprising: designating a variable bit rate ATM Adaptation Layer (AAL) protocol, AAL5, to define ATM cell traffic flow from the source to the destination; encoding a synchronous residual timestamp (SRTS) value indicative of the timing of a source clocking function using one or more sequence numbers and one or more portions of the SRTS value; creating an SRTS field in an AAL5 Common Part Convergence Sublayer Protocol Data Unit (CPCS-PDU) trailer to occupy at least a portion of the SRTS value; creating a sequence number (SN) field in the AAL5 CPCS-PDU trailer to occupy a sequence number corresponding to a sequence and completion status of segmented portions of the SRTS value; transmitting the CPCS-PDU, including the sequence number and the segmented portion of the SRTS value from the CPCS-PDU trailer, using the AAL5 protocol; receiving the ATM cells and corresponding SRTS values at the destination; decoding the SRTS value for use at the destination; and synchronizing a destination clocking function with the source clocking function by modifying the destination clocking function according to the SRTS values.
Claim 3
Dependent Claim 32 words
The method as in claim 1 , wherein creating an SRTS field in the AAL5 CPCS-PDU trailer comprises creating the SRTS field in the CPCS User-to-User (CPCS-UU) field of the CPCS-PDU trailer.
Claim 4
Dependent Claim 33 words
The method as in claim 1 , wherein creating an SRTS field in the AAL5 CPCS-PDU trailer comprises creating the SRTS field in the Common Part Indicator (CPI) field of the CPCS-PDU trailer.
Claim 5
Dependent Claim 32 words
The method as in claim 1 , wherein creating an SN field in the AAL5 CPCS-PDU trailer comprises creating the SN field in the CPCS User-to-User (CPCS-UU) field of the CPCS-PDU trailer.
Claim 6
Dependent Claim 33 words
The method as in claim 1 , wherein creating an SN field in the AAL5 CPCS-PDU trailer comprises creating the SN field in the Common Part Indicator (CPI) field of the CPCS-PDU trailer.
Claim 7
Dependent Claim 62 words
The method as in claim 1 , further comprising: determining whether the end of the SRTS value has been received at the destination based on the sequence number; and incrementing the sequence number in a subsequent ATM cell and providing an additional segmented portion of the SRTS value when the end of the SRTS value has not been received at the destination.
Claim 8
Dependent Claim 107 words
The method as in claim 1 , wherein transmitting the SRTS values with the ATM cells using AAL5 comprises: creating an SRTS field in an ATM payload section of the AAL5 Common Part Convergence Sublayer Protocol Data Unit (CPCS-PDU) to occupy at least a portion of the SRTS value; creating a sequence number (SN) field in the ATM payload section of the AAL5 CPCS-PDU to occupy a sequence number corresponding to a sequence and completion status of segmented portions of the SRTS value; transmitting the CPCS-PDU, including the sequence number and the segmented portion of the SRTS value from the ATM payload section, using the AAL5 protocol.
Claim 9
Dependent Claim 39 words
The method as in claim 7 , wherein creating an SRTS field and creating an SN field in the ATM payload section comprises creating the SRTS field and the SN field in the PCM synchronization field of the CPCS-PDU.
Claim 10
Dependent Claim 47 words
The method as in claim 1 , wherein: designating a variable bit rate AAL protocol comprises designating AAL2 to define the ATM cell traffic flow from the source to the destination; and transmitting the SRTS values comprises transmitting the SRTS values with the ATM cells using AAL2.
Claim 11
Dependent Claim 95 words
The method as in claim 9 , wherein transmitting the SRTS values with the ATM cells using AAL2 comprises: creating an SRTS field in an AAL2 Common Part Sublayer (CPS) packet to occupy at least a portion of the SRTS value; utilizing a sequence number (SN) field in the AAL2 CPS packet to occupy a sequence number corresponding to a sequence and completion status of segmented portions of the SRTS value; transmitting the CPS packet, including the sequence number and the segmented portion of the SRTS value from the CPS packet, using the AAL2 protocol.
Claim 12
Dependent Claim 32 words
The method as in claim 10 , wherein creating an SRTS field in the AAL2 CPS packet comprises creating the SRTS field in the User-to-User Indication (UUI) field of the CPS packet.
Claim 13
Dependent Claim 29 words
The method as in claim 10 , wherein utilizing the SN field in the AAL2 CPS comprises utilizing the SN field in the CPS-INFO field of the AAL2 CPS.
Claim 14
Dependent Claim 62 words
The method as in claim 10 , further comprising: determining whether the end of the SRTS value has been received at the destination based on the sequence number; and incrementing the sequence number in a subsequent ATM cell and providing an additional segmented portion of the SRTS value when the end of the SRTS value has not been received at the destination.
Claim 15
Dependent Claim 106 words
The method as in claim 9 , wherein transmitting the SRTS values with the ATM cells using AAL2 comprises: creating an SRTS field in an ATM payload section of the AAL2 Common Part Sublayer (CPS) packet to occupy at least a portion of the SRTS value; creating a sequence number (SN) field in the ATM payload section of the AAL2 CPS packet to occupy a sequence number corresponding to a sequence and completion status of segmented portions of the SRTS value; transmitting the CPS packet, including the sequence number and the segmented portion of the SRTS value from the ATM payload section, using the AAL2 protocol.
Claim 16
Dependent Claim 285 words
A cellular communications system for communicating voice information over a core network using Asynchronous Transfer Mode (ATM) technology and variable bit rates (VBR), the system comprising: at least one a base transceiver station (BTS) to communicate with at least one mobile station (MS), the BTS having a first ATM interface coupled to the core network; an Inter Working Function (IWF) having a second ATM interface coupled to the core network to communicate with the first ATM interface in the BTS via the core network; processing means for synchronizing variable bit rate traffic between the first and second ATM interfaces, the synchronization means comprising: means for designating a variable bit rate ATM Adaptation Layer (AAL) protocol to define ATM cell traffic flow between the first and second ATM interfaces; means for encoding a synchronous residual timestamp (SRTS) value indicative of the timing of a source clocking function using one or more sequence numbers and one or more portions of the SRTS value; means for creating an SRTS field in an AAL5 Common Part Convergence Sublayer Protocol Data Unit (CPCS-PDU) trailer to occupy at least a portion of the SRTS value; means for creating a sequence number (SN) field in the AAL5 CPCS-PDU trailer to occupy a sequence number corresponding to a sequence and completion status of segmented portions of the SRTS value; means for transmitting the CPCS-PDU, including the sequence number and the segmented portion of the SRTS value from the CPCS-PDU trailer, using the AAL5 protocol; means for receiving the ATM cells and corresponding SRTS values at a destination ATM interface; and means for synchronizing a destination clocking function with the source clocking function by modifying the destination clocking function according to the SRTS values.
Claim 17
Dependent Claim 285 words
A cellular communications system for communicating voice information over a core network using Asynchronous Transfer Mode (ATM) technology and variable bit rates (VBR), the system comprising: at least one a base transceiver station (BTS) to communicate with at least one mobile station (MS), the BTS having a first ATM interface coupled to the core network; an Inter Working Function (IWF) having a second ATM interface coupled to the core network to communicate with the first ATM interface in the BTS via the core network; processing means for synchronizing variable bit rate traffic between the first and second ATM interfaces, the synchronization means comprising: means for designating a variable bit rate ATM Adaptation Layer (AAL) protocol to define ATM cell traffic flow between the first and second ATM interfaces; means for encoding a synchronous residual timestamp (SRTS) value indicative of the timing of a source clocking function using one or more sequence numbers and one or more portions of the SRTS value; means for creating an SRTS field in an AAL5 Common Part Convergence Sublayer Protocol Data Unit (CPCS-PDU) trailer to occupy at least a portion of the SRTS value; means for creating a sequence number (SN) field in the AAL5 CPCS-PDU trailer to occupy a sequence number corresponding to a sequence and completion status of segmented portions of the SRTS value; means for transmitting the CPCS-PDU, including the sequence number and the segmented portion of the SRTS value from the CPCS-PDU trailer, using the AAL5 protocol; means for receiving the ATM cells and corresponding SRTS values at a destination ATM interface; and means for synchronizing a destination clocking function with the source clocking function by modifying the destination clocking function according to the SRTS values.

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2006-04-28 2006-10-28 2007-04-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2010-04-28 2010-10-28 2011-04-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2014-04-28 2014-10-28 2015-04-29 $7700.00 Window Closed / Lapsed

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