Patent EP0473330A1 successfully refreshed from Google Patents.
EP0473330A1
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Serving constant bit rate traffic in a broadband data switch
Assignee: AT&T Inc
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Filing: 1991-08-13
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Granted: —
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Expires: 2011-08-13
Abstract
Abstract This invention relates to a method and apparatus for transmitting constant and variable bit rate traffic in a broadband ISDN switch. Data from constant bit rate sources such as television cameras is entered into a group of queues (134,136,138,139). Each member of the group for queuing data of a different band of bit rates. Data is transmitted from these queues with highest priority from the queue storing data of the highest band of bit rates. If the longest enqueued entity of data in one of the other queues has been enqueued for more than a prespecified period, its priority is increased. Analytic studies have shown that use of three queues for constant bit rate traffic and a fourth queue for variable bit rate traffic allows a high occupancy in the output channels to be maintained with a negligible number of data entities excessively delayed.
Inventors
- 👤 Vikram Punj
- 👤 Albert Kai-Sun Wong
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 18:47
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/54; H04L12/56; H04L12/5601; H04L12/5602; H04L49/00; H04L49/30; H04L49/3081; H04L2012/5638; H04L2012/5646; H04L2012/5649; H04L2012/5651; H04L2012/5678; H04L2012/5679; H04L2012/5681
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
55 words
A method of transmitting packetized data traffic from a number of sources having different bit rates comprising the steps of: entering data from sources having different bands of bit rates in different queues; and transmitting data from queues serving higher bit rate sources with higher priority than data from queues serving lower bit rate sources.
Claim 2
Dependent Claim
66 words
The method of claim 1 wherein some of said sources generate constant bit rate data and others generate variable bit rate data, wherein separate queues are used for serving constant bit rate data sources and variable bit rate data sources and wherein said transmitting comprises transmitting data from queues serving constant bit rate sources with higher priority than data from queues serving variable bit rate sources.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said transmitting step comprises transmitting data from the queue with the highest priority having enqueued data to be transmitted.
Claim 4
Dependent Claim
34 words
The method of claim 3 wherein the priority of an oldest enqueued entity of data in a queue is increased if it has been enqueued for more than a predefined time for said queue.
Claim 5
Dependent Claim
35 words
The method of claim 4 wherein the time that said oldest enqueued entity of data has been enqueued is measured only from the time that said entity has been an oldest entity in the queue.
Claim 6
Dependent Claim
149 words
Apparatus for transmitting packetized data from a plurality of sources having different bit rates comprising: a plurality of queues for storing entities of data, each queue for storing data from sources having a different band of bit rates; processor means operative under the control of a first program for controlling storage of data from each of said sources into one of said queues, said one queue for storing data of a band of bit rates including a bit rate of said each source; and said processor means further operative under the control of a second program for controlling transmission of data stored in said queues, transmission of data from a queue for storing a first band of bit rates being given priority over transmission of data from a queue for storing a second band of bit rates, wherein said first band has higher bit rates than said second band.
Claim 7
Dependent Claim
73 words
The apparatus of claim 6 wherein said plurality of queues comprises a plurality of queues for storing data from sources generating constant bit rate data, wherein said processor means are further operative under the control of said second program for controlling transmission of data stored in said queues for storing data from sources generating constant bit rate data with higher priority than data for queues storing data from sources generating variable bit data.
Claim 8
Dependent Claim
36 words
The apparatus of claim 6 wherein the priority of an oldest enqueued entity of data in a queue is increased if it has been enqueued for more than a predefined length of time for said queue.
Claim 9
Dependent Claim
37 words
The apparatus of claim 8 wherein a length of time that said oldest enqueued entity of data has been enqueued is measured only from a time that said entity has been an oldest entity in the queue.
Claim 10
Independent Claim
175 words
A method of transmitting packetized data traffic from a number of constant bit rate sources having different bit rates, said bit rates divided into a plurality of disjoint bands of bit rates, and another number of variable bit rate sources, comprising the steps of: entering data from constant bit rate sources in ones of a plurality of first queues, each first queue for serving one of said different bands of bit rates; entering data from variable bit rate sources in a second queue; transmitting, data from a first queue serving a higher constant bit rate band with higher priority than data from a first queue serving a lower constant bit rate band, and wherein said second queue has lower priority than any of said first queues wherein the priority of an oldest enqueued entity of data in a queue is increased if it has been an oldest enqueued entity enqueued for more than a predefined time, and wherein transmitting comprises transmitting data from the queue with the highest priority having enqueued data to be transmitted.
Claim 11
Dependent Claim
64 words
The method of claim 10 wherein said first queues comprise three queues, one for storing data from constant bit rate sources generating data in excess of approximately 15 megabits per second, one for storing data from constant bit rate sources generating data at rates at or below approximately 1.5 megabits per second, and one for rates between approximately 1.5 and 15 megabits per second.
Claim 12
Dependent Claim
17 words
The method of claim 11 wherein said data entities are cells of an asynchronous transfer mode frame.
Claim 13
Dependent Claim
49 words
The method of claim 12 wherein an oldest enqueued cell of one of said first queues has its priority increased by one level when it has been an oldest enqueued cell for approximately one cell interval of a highest bit rate of a band of said one first queue.
References Cited (Backward Citations)
EP0171596A2
Cited
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