Multiplex communications – Communication techniques for information carried in plural... – Adaptive
Reexamination Certificate
1999-11-15
2003-10-14
Nguyen, Chau (Department: 2663)
Multiplex communications
Communication techniques for information carried in plural...
Adaptive
C370S395100
Reexamination Certificate
active
06633586
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method for determining an individualized-connection currently allowed transmission rate of ATM cells of virtual connections having variable transmission rates, which utilize time change information allocated to transmission rate changes within an ATM communication system.
2. Description of the Prior Art
A large variety of monitoring procedures are used to monitor variable transmission rates of ATM (asynchronous transfer mode) cells of virtual connections within an ATM communication network (as well as other existing and future packet-oriented communications systems). One such procedure is known as the “Dynamic Generator Cell Rate Algorithm (DGCRA)”, described in the ITU I.371.1; it is used particularly for ABR (Available Bit Rate) connections within an ATM communication network.
Overload situations in an ATM communication system can be recognized with the assistance of the DGCRA monitoring procedure and measures can be subsequently initiated for eliminating such overload conditions. In order to be able to assure an efficient monitoring of the variable transmission rates for ABR traffic within an ATM communication system, the currently allowed transmission rate (at any specific point in time—generally referred to as “Allowed Cell Rate” (ACR)) is continuously required for implementing the DGCRA monitoring procedure. The currently allowed transmission rate of ATM cells thus describes the transmission rate to be monitored at the time of the monitoring procedure.
Connection-related data as well as data describing the current condition of the connection segments are additionally communicated to the receiver via the resource managements cells transmitted in a second communication direction. These are communicated with the assistance of resource management cells (RM), i.e., control cells periodically inserted into the cell stream by a transmission device in a first communication direction opposite the second.
After the arrival of a resource management cell communicated in a second transmission direction in an ATM communication system, a check is carried out (among other things) to see whether the explicit transmission rate entered in the resource management cell can be made available by an ATM communication system for the existing, virtual connection. A further check is carried out to see whether an adaptation of the explicit transmission rate is required in order to avoid a data jam in the ATM communication system. When this is the case, the explicit transmission rate read from the resource management cell is then replaced by the transmission rate that can be communicated from the ATM communication system. This assures that the receiver is informed of the explicit transmission rate by the resource management cell, namely the transmission rate with which data can be sent without causing a traffic jam.
For determining the currently allowed transmission rate, proposal I.371.1, (Traffic Control and Congestion Control in B-ISDN: Conformance Definitions for ABT and ABR” of the International Telecommunication Union (ITU)) defines, among other things, two individualized-connection delay times providing assistance for calculating the point in time of an increase or, respectively, lowering of transmission rate with respect to the currently allowed transmission rate of ATM cells of a virtual connection. The proposal also explains a method for determining the currently allowed transmission rate of ATM cells with the assistance of three intermediately stored transmission rates and the appertaining time change information.
Applying this method, both the currently allowed transmission rate as well as the appertaining time change information for monitoring this transmission rate are calculated proceeding from the explicit transmission rate of ATM cells read from an incoming resource management cell. The currently allowed transmission rate is adapted to the modified transmission rate with the assistance of counters, two counters are required for each connection for determining a first and a second time change information.
When the counter representing a first time change information runs down, the currently allowed transmission rate is set to the previously determined new value with the assistance of an adaptation routine, and the first time change information is replaced by a second time change information. Subsequently, the updated currently allowed transmission rate of ATM cells is monitored by the DGCRA monitoring procedure until the counter representing a current time change information has run down and a correction of the currently allowed transmission rate is required.
Each virtual connection is provided at least two counters for the realization of the time change information, and at least three memory units for storing the transmission rates for the determination of the respective, per-call, currently allowed transmission rate of ATM cells.
SUMMARY OF THE INVENTION
The object of the invention is to improve the determination of the currently allowed transmission rate of ATM cells of virtual connections of an ATM communication system. This object is achieved by utilizing time change information allocated to transmission rate changes within an ATM communication system for determining the individualized-connection currently allowed transmission rate, intermediately storing a determined individualized-connection transmission rate of ATM cells, if it exists, in a memory unit, intermediately storing time change information relating to the transmission rate, if the time change information exists, in the memory unit, calculating the time change information using two individualized-connection prescribable delay times and utilizing a transmission rate handling routine, updating the time change information if it upwardly exceeds a predetermined time span by an updating routine, utilizing a current time value of a calendar information and an individualized-connection calendar information, utilizing a list parameter to indicate relative size relationships among a plurality of current the intermediately stored transmission rates, and determining the currently allowed transmission rate and updating the list parameter using the list parameter.
The basic aspect of the inventive method is in intermediately storing: 1) a per-call specific transmission rate of ATM cells (if it exists), and 2) appertaining time change information (if it exists); these are stored in a memory unit in the determination of the currently allowed transmission rate of ATM cells of virtual connections with variable transmission rates. They are, in addition, stored with the assistance of time change information within an ATM communication system allocated to transmission rate changes. Furthermore, the calculation of the time change information of transmission rate changes ensues with the assistance of two per-call prescribable delay times, ensuing with a transmission rate handling routine. The time change information following the expiration of a predetermined time span are updated by an updating routine with the assistance of a current time value, a calendar information and an individualized-connection calendar information.
The plurality of current intermediately stored transmission rates and their size relationship relative to one another is displayed with the assistance of a list parameter, whereby the determination of the currently allowed transmission rate and an updating of the list parameter value ensues with the assistance of the list parameter value. The employment of a simple, additional list parameter yields the advantage that the maximum transmission rate of ATM cells defined in the proposal I.371.1, “Traffic Control and Congestion Control in B-ISDN: Conformance Definitions for ABT and ABR” of the ITU is not required in the inventive method, and, thus, need not be stored and processed. This eliminates the use of memory and dynamically relieves the ATM communications system, even in light of the dynamically processed list parameter.
Moreover, the u
Fish & Richardson P.C.
Juntima Nittaya
Nguyen Chau
Siemens Aktiengesellschaft
LandOfFree
Method for individualized-connection determination of the... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for individualized-connection determination of the..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for individualized-connection determination of the... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3158575