US6859442B1
Expired / Lapsed
US
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Method and system for transport of frame relay traffic over satellite/wireless networks
Assignee: Viasat Inc
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Filing: 1998-10-20
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Granted: 2005-02-22
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Expires: 2018-10-20
Abstract
Abstract To efficiently transmit frame relay packets between terrestrial frame relay networks ( 10, 12 ) over a satellite/wireless network ( 14 ), the packets are processed by frame relay processors ( 16, 18 ) at both ends of the satellite/wireless network ( 14 ). Variable length frame relay packets are segmented into smaller packets called spackets. The system utilizes priority queueing and a scheduler ( 24 ) transmits the spackets over the satellite/wireless link. To enhance the quality of the satellite/wireless link, each frame contains a variable number of Reed-Solomon (RS) check bytes used for error correction. Further, several frames are interleaved before transmission over the satellite/wireless link to spread the effect of burst errors over several frames. Additionally, a header compression technique saves bandwidth by compressing a Virtual Circuit (VC) identifier of the frame relay packet into a smaller value and maps the VCs to a value as specified by the size of the compressed VC field.
Inventors
- 👤 Anil K. Agarwal
- 👤 Sampath V. Kumar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:00
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/185; H04B7/18578; H04B7/18582; H04L; H04L12/00; H04L12/28
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
92 words
A method of transporting frame relay data over a satellite or wireless network, comprising the steps of: receiving frame relay packets from a frame relay network; prioritizing the frame relay packets; segmenting the payload data of each of the frame relay packets to form spackets; scheduling transmission of the spackets in accordance with priorities of the frame relay packets to which the spackets correspond; forming fixed-sized satellite/wireless frames, each containing plural spackets and a variable number of error correction code bytes; and transmitting the satellite/wireless frames over the satellite or wireless network.
Claim 2
Independent Claim
92 words
A method of transporting frame relay data over a satellite or wireless network, comprising the steps of: receiving frame relay packets from a frame relay network; prioritizing the frame relay packets; segmenting the payload data of each of the frame relay packets to form spackets; scheduling transmission of the spackets in accordance with priorities of the frame relay packets to which the spackets correspond; forming fixed-sized satellite/wireless frames, each containing plural spackets and a variable number of error correction code bytes; and transmitting the satellite/wireless frames over the satellite or wireless network.
Claim 3
Dependent Claim
21 words
The method according to claim 1 , further comprising the step of compressing the spackets prior to forming the satellite/wireless frames.
Claim 4
Dependent Claim
36 words
The method according to claim 1 , wherein said prioritizing step includes queuing the spackets in a plurality of data queues as a function of priorities of the frame relay packets to which the spackets correspond.
Claim 5
Dependent Claim
17 words
The method according to claim 3 , wherein the plurality of queues correspond to different priority levels.
Claim 6
Dependent Claim
19 words
The method according to claim 3 , wherein the plurality of queues correspond to a plurality of virtual channels.
Claim 7
Dependent Claim
52 words
The method according to claim 1 , wherein said segmenting step includes segmenting the payload data of each of the frame relay packets into plural spackets, wherein all of the plural spackets, except a last of the plural spackets, is required to be n bytes in length, where n is an integer.
Claim 8
Dependent Claim
18 words
The method according to claim 1 , wherein said segmenting step includes prepending each spacket with a header.
Claim 9
Dependent Claim
74 words
The method according to claim 7 , wherein the header of each spacket includes: a packet number indicating to which frame relay packet the spacket corresponds; a sequence number indicating the position of the spacket within the frame relay packet; a VC Id field indicating the virtual channel to which the frame relay packet corresponds; and a last field indicating whether or not the spacket is the last spacket in the frame relay packet.
Claim 10
Dependent Claim
29 words
The method according to claim 8 , wherein a VC identifier contained in the VD Id field is compressed from a VC identifier contained in the frame relay packet.
Claim 11
Dependent Claim
19 words
The method according to claim 1 , wherein the spackets contained within a satellite/wireless frame are variable in size.
Claim 12
Dependent Claim
17 words
The method according to claim 1 , wherein a single spacket is transmittable over plural satellite/wireless frames.
Claim 13
Dependent Claim
43 words
The method according to claim 1 , wherein said forming step includes forming an interleaver frame from plural satellite/wireless frames, wherein the order of the bytes in the interleaver frame is rearranged to spread the effects of burst errors over several satellite/wireless frames.
Claim 14
Dependent Claim
51 words
The method according to claim 1 , further comprising the step of monitoring the condition of a link over the satellite or wireless network, wherein said forming step further comprises varying the variable number of error correction code bytes in response to variations in link conditions observed in said monitoring step.
Claim 15
Dependent Claim
38 words
The method according to claim 13 , wherein said monitoring step includes calculating a byte error ratio and said forming step includes setting the number of error correction code bytes as a function of the byte error ratio.
Claim 16
Dependent Claim
33 words
The method according to claim 14 , wherein the byte error ratio is calculated more quickly when the bit error rate is high and more slowly when the bit error rate is low.
Claim 17
Dependent Claim
18 words
The method according to claim 14 , wherein the error correction code bytes are Reed-Solomon coding check bytes.
Claim 18
Dependent Claim
22 words
The method according to claim 14 , wherein the error correction code bytes are Reed-Solomon coding check bytes and Viterbi control codes.
Claim 19
Dependent Claim
38 words
The method according to claim 1 , wherein each fixed-sized satellite/wireless frame formed in said forming step includes: a header, a payload comprising a variable number of variable-size spackets, and the variable number of error correction code bytes.
Claim 20
Dependent Claim
90 words
The method according to claim 18 , wherein the header of each satellite/wireless frame includes: a field indicating the number of spackets in the frame; a field indicating a size of a first partial spacket in the frame; a field indicating a sequence number of the frame; a field indicating the number of error correction code bytes in the frame; a field indicating the number of error correction code bytes to be used in frames to be received; and a field indicating whether the spackets in the frame are compressed.
Claim 21
Dependent Claim
64 words
The method according to claim 19 , wherein the field indicating the number of error correction code bytes in the frame, the field indicating the number of error correction code bytes to be used in frames to be received, and the field indicating whether the spackets in the frame are compressed are inserted in a same field location in frames having different frame numbers.
Claim 22
Dependent Claim
18 words
The method according to claim 18 , wherein the error correction code bytes are Reed-Solomon coding check bytes.
Claim 23
Dependent Claim
52 words
The method according to claim 1 , further comprising the steps of: receiving satellite/wireless frames from the satellite or wireless network; resequencing the spackets contained in the received satellite/wireless frames and reassembling the frame relay packets from the resequenced spackets; and transmitting the reassembled frame relay packets to the frame relay network.
Claim 24
Dependent Claim
20 words
The method according to claim 22 , further comprising the step of decompressing the spackets prior to resequencing the spackets.
Claim 25
Independent Claim
119 words
A system for processing frame relay data to be transported over a satellite or wireless network, comprising: a frame relay physical and data link layer processor for receiving frame relay packets from a frame relay network; a prioritizer for prioritizing the frame relay packets; a segmentation processor for segmenting the payload data of each of the frame relay packets to form spackets; a scheduler for scheduling transmission of the spackets in accordance with priorities of the frame relay packets to which the spackets correspond; and a satellite/wireless frame processor adapted to form fixed-sized satellite/wireless frames to be transmitted over the satellite or wireless network, each of the fixed-sized satellite/wireless frames including a variable number of error correction code bytes.
Claim 26
Independent Claim
119 words
A system for processing frame relay data to be transported over a satellite or wireless network, comprising: a frame relay physical and data link layer processor for receiving frame relay packets from a frame relay network; a prioritizer for prioritizing the frame relay packets; a segmentation processor for segmenting the payload data of each of the frame relay packets to form spackets; a scheduler for scheduling transmission of the spackets in accordance with priorities of the frame relay packets to which the spackets correspond; and a satellite/wireless frame processor adapted to form fixed-sized satellite/wireless frames to be transmitted over the satellite or wireless network, each of the fixed-sized satellite/wireless frames including a variable number of error correction code bytes.
Claim 27
Dependent Claim
23 words
The system according to claim 24 , further comprising a data compressor for compressing the spackets prior to formation of the satellite/wireless frames.
Claim 28
Dependent Claim
34 words
The system according to claim 24 , wherein said prioritizer queues the spackets in a plurality of data queues as a function of priorities of the frame relay packets to which the spackets correspond.
Claim 29
Dependent Claim
17 words
The system according to claim 26 , wherein the plurality of queues correspond to different priority levels.
Claim 30
Dependent Claim
19 words
The system according to claim 26 , wherein the plurality of queues correspond to a plurality of virtual channels.
Claim 31
Dependent Claim
51 words
The system according to claim 24 , wherein said segmentation processor segments the payload data of each of the frame relay packets into plural spackets, wherein all of the plural spackets, except a last of the plural spackets, is required to be n bytes in length, where n is an integer.
Claim 32
Dependent Claim
17 words
The system according to claim 24 , wherein said segmentation processor prepends each spacket with a header.
Claim 33
Dependent Claim
74 words
The system according to claim 30 , wherein the header of each spacket includes: a packet number indicating to which frame relay packet the spacket corresponds; a sequence number indicating the position of the spacket within the frame relay packet; a VC Id field indicating the virtual channel to which the frame relay packet corresponds; and a last field indicating whether or not the spacket is the last spacket in the frame relay packet.
Claim 34
Dependent Claim
29 words
The system according to claim 31 , wherein a VC identifier contained in the VD Id field is compressed from a VC identifier contained in the frame relay packet.
Claim 35
Dependent Claim
19 words
The system according to claim 24 , wherein the spackets contained within a satellite/wireless frame are variable in size.
Claim 36
Dependent Claim
17 words
The system according to claim 24 , wherein a single spacket is transmittable over plural satellite/wireless frames.
Claim 37
Dependent Claim
43 words
The system according to claim 24 , wherein said satellite/wireless frame processor forms an interleaver frame from plural satellite/wireless frames, wherein the order of the bytes in the interleaver frame is rearranged to spread the effects of burst errors over several satellite/wireless frames.
Claim 38
Dependent Claim
41 words
The system according to claim 24 , wherein said satellite/wireless frame processor monitors the condition of a link over the satellite or wireless network and varies the variable number of error correction code bytes in response to variations in link conditions.
Claim 39
Dependent Claim
34 words
The system according to claim 36 , wherein said satellite/wireless frame processor calculates a byte error ratio and sets the number of error correction code bytes as a function of the byte error ratio.
Claim 40
Dependent Claim
33 words
The system according to claim 37 , wherein the byte error ratio is calculated more quickly when the bit error rate is high and more slowly when the bit error rate is low.
Claim 41
Dependent Claim
18 words
The system according to claim 36 , wherein the error correction code bytes are Reed-Solomon coding check bytes.
Claim 42
Dependent Claim
22 words
The system according to claim 36 , wherein the error correction code bytes are Reed-Solomon coding check bytes and Viterbi control codes.
Claim 43
Dependent Claim
33 words
The system according to claim 24 , wherein each fixed-sized satellite/wireless frame includes: a header, a payload comprising a variable number of variable-size spackets, and the variable number of error correction code bytes.
Claim 44
Dependent Claim
90 words
The system according to claim 41 , wherein the header of each satellite/wireless frame includes: a field indicating the number of spackets in the frame; a field indicating a size of a first partial spacket in the frame; a field indicating a sequence number of the frame; a field indicating the number of error correction code bytes in the frame; a field indicating the number of error correction code bytes to be used in frames to be received; and a field indicating whether the spackets in the frame are compressed.
Claim 45
Dependent Claim
64 words
The system according to claim 42 , wherein the field indicating the number of error correction code bytes in the frame, the field indicating the number of error correction code bytes to be used in frames to be received, and the field indicating whether the spackets in the frame are compressed are inserted in a same field location in frames having different frame numbers.
Claim 46
Dependent Claim
18 words
The system according to claim 41 , wherein the error correction code bytes are Reed-Solomon coding check bytes.
Claim 47
Dependent Claim
70 words
The system according to claim 24 , further comprising: a receive satellite/wireless frame processor for receiving satellite/wireless frames from the satellite or wireless network; a reassembly and resequencer processor for resequencing the spackets contained in the received satellite/wireless frames and reassembling the frame relay packets from the resequenced spackets; wherein said frame relay physical and data link layer processor transmits the reassembled frame relay packets to the frame relay network.
Claim 48
Dependent Claim
21 words
The system according to claim 45 , further comprising a data decompressor for decompressing the spackets prior to resequencing the spackets.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2008-02-22 | 2008-08-23 | 2009-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2012-02-22 | 2012-08-23 | 2013-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2016-02-22 | 2016-08-23 | 2017-02-22 | $7700.00 | Window Closed / Lapsed |