A method and system for combining requests for data bandwidth by a data source for transmission of data over a wireless communication medium is provided. A central node receives one or more bandwidth requests from one or more data sources via wireless communication. A scheduler then combines one or more bandwidths requests from the same data source to create a single data burst bandwidth. The central node then grants the data burst bandwidth to the appropriate data source via wireless communication.
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1. A method for combining requests for bandwidth by a data source for transmission of data over a wireless network, comprising:
scheduling bandwidth requests that each include a data source identifier, a priority identifier and an amount of required bandwidth from one or more data sources in an order to be serviced based on the priority identifier associated with each bandwidth request and an order in which each bandwidth request was received; and
combining the amount of required bandwidth specified by each of the scheduled bandwidth requests having the same data source identifier into a data burst bandwidth.
7. A method for combining requests for bandwidth by a data source for transmission of data over a wireless network, comprising:
creating a data burst bandwidth from bandwidth requests from one or more data sources, each bandwidth request having a data source identifier, a priority identifier and an amount of required bandwidth, wherein the data burst bandwidth combines the amount of required bandwidth specified by each of the bandwidth requests having the same data source identifier and priority identifier into a data burst bandwidth; and
scheduling a granting of each data burst bandwidth based on one or more quality of service parameters.
2. The method of
servicing bandwidth requests having a higher priority identifier before bandwidth requests having a lower priority identifier and servicing bandwidth requests having the same priority identifier according to the order in which the bandwidth requests were received.
3. The method of
combining the amount of required bandwidth specified by each of the scheduled bandwidth requests having the same data source identifier but having different priority identifiers into a data burst bandwidth.
4. The method of
storing each of the bandwidth requests in a data structure so as to maintain the order in which the bandwidth requests were received.
5. The method of
6. The method of
8. The method of
9. The method of
10. The method of
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This application is a continuation of U.S. patent application Ser. No. 09/783,311, filed Feb. 15, 2001, now U.S. Pat. No. 6,999,414, issued Feb. 14, 2006, which is a continuation-in-part of U.S. patent application Ser. No. 09/427,792, filed Oct. 27, 1999, now U.S. Pat. No. 6,804,251, issued Oct. 12, 2004, both of which are herein incorporated by reference in their entireties.
U.S. patent application Ser. No. 09/783,311, filed Feb. 15, 2001, claims the benefit of U.S. Provisional Application No. 60/182,470, filed Feb. 15, 2000; U.S. Provisional Application No. 60/247,188, filed Nov. 9, 2000; U.S. Provisional Application No. 60/254,415, filed Dec. 8, 2000; U.S. Provisional Application No. 60/262,201, filed Jan. 17, 2001; and U.S. Provisional Application No. 60/262,203, filed Jan. 17, 2001, all of which are herein incorporated by reference in their entireties.
U.S. patent application Ser. No. 09/783,311, filed Feb. 15, 2001, is related to U.S. patent application Ser. No. 09/783,404, filed Feb. 15, 2001; U.S. patent application Ser. No. 09/785,020, filed Feb. 15, 2001; U.S. patent application Ser. No. 09/783,405, filed Feb. 15, 2001; and U.S. patent application Ser. No. 09/783,403, filed Feb. 15, 2001, all of which are herein incorporated by reference in their entireties.
1. Field of the Invention
The present invention is generally related to increasing the efficiency of providing requested bandwidth to a data source via wireless communication mediums.
2. Background Art
The importance to the modern economy of rapid data access and exchange cannot be overstated. This explains the exponentially increasing popularity of the data access and exchange via cable networks (including coaxial cable or Hybrid fiber coaxial cable), the Internet, intranets, wireless networks, satellites and so forth (i.e., communication mediums). Rapid data access and exchange is partly dependent upon how efficiently bandwidth is allocated to a data provider in order for the data provider to transfer the requested data to a user via one of the communication mediums mentioned above.
One very desirable solution for rapid data access and exchange is via cable networks and cable modems. Cable modems provide asynchronous communications on cable networks. In general, a user connects a cable modem to the TV outlet for his or her cable TV, and the cable TV operator connects a cable modem termination system (“CMTS”) in the operator's headend. The CMTS is a central device for connecting the cable network to a data network like the Internet. The CMTS is a central distribution point for a cable system. Data flows “downstream” from the CMTS to the cable modem (i.e., downstream communication). Alternatively, data flows “upstream” from the cable modem to the CMTS (i.e., upstream communication).
A common cable modem standard today is the Data Over Cable Service Interface Specification (“DOCSIS”). DOCSIS defines technical specifications for both cable modems and CMTS. DOCSIS downstream communication is quite restrictive in the way the control information is conveyed to the data provider (e.g., cable modem) via a DOCSIS CMTS scheduler. What is needed is to override the CMTS scheduler of DOCSIS and provide a CMTS scheduler that reduces the overhead of bandwidth grants via downstream communication by providing flexibility in the allocation of the bandwidth.
The present invention is a system and method for combining requests for bandwidth by a data source for transmission of data over a wireless communication medium.
In particular, a method for combining requests for bandwidth by a data source for transmission of data over a wireless network is provided. In accordance with this method, bandwidth requests are received from one or more data sources, each bandwidth request having a data source identifier, a priority identifier, and an amount of required bandwidth. Each of the bandwidth requests are scheduled in an order to be serviced based on the priority identifier associated with each bandwidth request and an order in which each bandwidth request was received. The amount of required bandwidth specified by each of the scheduled bandwidth requests having the same data source identifier is combined into a data burst bandwidth. Each data burst bandwidth is granted to a respective data source over the wireless network.
An alternative method for combining requests for bandwidth by a data source for transmission of data over a wireless network is also provided. In accordance with this method, bandwidth requests are received from one or more data sources, each bandwidth request having a data source identifier, a priority identifier, and an amount of required bandwidth. The amount of required bandwidth specified by each of the bandwidth requests having the same data source identifier and priority identifier is combined into a data burst bandwidth. The granting of each data burst bandwidth is then scheduled based on one or more quality of service parameters.
The present invention will be described with reference to the accompanying drawings, wherein:
For illustration purposes, the present invention is described in terms of being utilized with a cable network. It should be understood that the present invention is not limited to use with a cable network. In fact, the present invention may be used with any communication medium, including but not limited to, the Internet, intranets, fiber optic networks, wireless networks and satellites.
Data in the present invention includes any type of information. This includes, but is not limited to, digital, voice, video, audio, etc.
In general, cable modem 104 forwards or provides data via asynchronous communications on cable networks. Cable modem 104 receives data from a user that needs to be transferred via a cable network. In order to do this, cable modem 104 requests that CMTS 102 grant to it the necessary bandwidth.
As mentioned, cable modem 104 receives data from a user to be transferred via a cable network. Different types of data require different modes of transfer since the importance of timing is different with different types of data. For example, voice data cannot tolerate delays in its transfer. Alternatively, the type of data involved in web surfing can tolerate delays in its transfer.
In order to ensure the importance of timing is maintained, cable modem 104 assigns different priority identifiers to different types of data. The higher the priority a data has, the less of a delay that type of data will experience in its transfer via the cable network. Thus, voice data would be assigned a priority identifier with a higher priority than data involved in web surfing.
Cable modem scheduler 116 is coupled to cable modem 104. Cable modem scheduler 116 is described in detail in related U.S. patent application Ser. No. 09/783,404, filed Feb. 15, 2001. In general, cable modem scheduler 116 is responsible for multiplexing the internal traffic, (i.e., requesting the necessary bandwidth that cable modem 116 needs to transfer its current types of data). Cable modem scheduler 116 must take into consideration the different priorities given to the current data to be transferred and to request bandwidth from CMTS 102 accordingly.
As stated above, DOCSIS is a common cable modem standard used today. DOCSIS provides standard centralized scheduling decisions that do not allow for flexibility in terms of deciding when cable modem 104 requests bandwidth from CMTS 102 in order to transfer its current data. Cable modem scheduler 116 defines an architecture that overrules this DOCSIS standard in a seamless manner. Some of the main differences between the DOCSIS standard and cable modem scheduler 116 are described next.
One main difference between the DOCSIS standard and cable modem scheduler 116 includes the decoupling of the request phase with the grant phase (i.e., grants of bandwidth received from CMTS 102). Here, cable modem scheduler 116 uses granted bandwidth as they are received regardless of their size and priority specification, thereby ignoring the DOCSIS standard. Cable modem scheduler 116 ignores the priority id of the granted bandwidth. This means that cable modem scheduler 116 does not have to use the granted bandwidth in the same order in which it was requested. In addition, piggyback requests may be separate requests for bandwidth instead of extended header as done in the DOCSIS standard. How piggyback requests are handled by the present invention are described in detail in related U.S. patent application Ser. No. 09/783,404, filed Feb. 15, 2001. Here, it is important to note that piggybacks requests are treated as separate requests for bandwidth and may or may not be given a priority identifier. In an embodiment, the present invention assigns voice data the highest priority, piggyback requests have the second highest priority and other types of data (including data required for web surfing) is given the lowest priority.
Therefore, cable modem scheduler 116 sends bandwidth requests to CMTS 102 via upstream communication 108. At a high level, each bandwidth request may include three fields. The three fields are a data provider identifier, a priority identifier, and the amount of required bandwidth. In an embodiment of the present invention, the bandwidth request does not include the data provider identifier as a field. Here, the data provider identifier is implicit (e.g., piggyback requests). These three fields will be briefly described next.
Each cable modem 104 has a unique data provider identifier. CMTS 102 uses this identifier to grant the requested bandwidth to cable modem 104. Priority identifiers indicate the priority given to the data and thus indicating the type of data that will be transferred over the cable network via the granted bandwidth. Finally, the last field is value indicating the amount of required bandwidth needed to transfer the data. CMTS 102, CMTS scheduler 110 and data structure 112 will now be described.
CMTS 102 is a central device for connecting the cable network to a data network. CMTS scheduler 102 is a bandwidth manager. CMTS scheduler 102, as a bandwidth manager, decides how to grant available bandwidth according to the current bandwidth requests. This grant is done via downstream communication 106 in such as way as to reduce overhead. This ability to decide how to grant available bandwidth provides flexibility. This flexibility allows the present invention to reduce the overhead involved in granting bandwidth to cable modem 104 via downstream communication. Data structure 112 is used to organized the received bandwidth requests in such as way as to take into consideration the type of data (via the priority identifiers) and the order in which the requests were received.
As described above, the way in which the DOCSIS CMTS scheduler grants bandwidth is quite restrictive, thus creating unnecessary overhead in downstream communication. The details of how CMTS scheduler 110 grants bandwidth to cable modem 104 so that to decrease overhead will be described in detail below. The overhead in each granted bandwidth will be described next with reference to
Overhead 204 may be referred to as the physical layer overhead. Regardless of the size of granted bandwidth 202, overhead 204 uses approximately the same amount of bytes. Where the preamble and guard band are typically fixed in size, the FEC is a variable size that depends on the amount of bandwidth. Therefore, the larger the granted bandwidth, the greater the efficiency. However, larger granted bandwidths mean greater end-to-end delay experienced by a voice call, for example. Thus, when granting bandwidth, end-to-end delay versus gained efficiency must be taken into consideration.
Different systems may reserve different amount of bytes for overhead 204. How the present invention combines bandwidth requests from the same cable modem 104 to create a single data burst bandwidth is described next.
As mentioned above, cable modem scheduler 116 may send different bandwidth requests to CMTS 102, including but not limited to, voice, piggyback and data for activities such as web surfing. Thus, at any given time, CMTS 102 may have more than one request for the same cable modem. This is especially true since cable modem scheduler 104 piggybacks requests as often as possible. These requests may have different priority identifiers values or the same priority identifier value for data that has arrived at CMTS 102 at different times.
A goal of the present invention is to combine all pending bandwidth requests from the same cable modem into one data burst bandwidth request. Here, instead of individual requests being granted which would require physical overhead for each grant, the present invention reduces the physical over to one for all of the individual requests by combining them. This can be accomplished by the present invention partly because there is a decoupling of the request phase (i.e., bandwidth requests from cable modem 104) with the grant phase (i.e., grants of bandwidth received from CMTS 102), as mentioned above. CMTS scheduler 110 needs to take into consideration end-to-end delay verses the gained efficiency.
In
In step 304, CMTS scheduler 110 combines one or more bandwidths requests from the same cable modem 104 to create a single data burst bandwidth. Control then passes to step 306.
In step 306, CMTS 102 grants the data burst bandwidth to the appropriate cable modem 104 via downstream communication 106. The flowchart in
As illustrated in
Each bandwidth request is indicated as (n,m), where n is the data provider identifier and m is the amount of required bandwidth. As described above, each bandwidth request includes at least three fields, including the data provider identifier, the priority identifier, and the amount of required bandwidth. For example, bandwidth request 510 has a priority identifier value of 0, the cable modem 104 who sent the request has the data provider identifier of 1 and it is requesting 5 units of bandwidth. In addition, bandwidth request 510 arrived at CMTS 102 before bandwidth request 512, which in turn arrived before bandwidth request 514, as indicated by their positions in queue 502. It is important to note that bandwidth request 516 may arrive at CMTS 102 before bandwidth request 514, but bandwidth request 514 is still likely to be granted bandwidth first due to it having a higher priority identifier.
Also illustrated by
In step 404, CMTS scheduler 110 schedules each bandwidth request stored in data structure 112 in an order to be serviced by the present invention. Here, bandwidth requests are scheduled to be serviced based on priority identifiers (i.e., type of data) and the order in which the requests for bandwidth were received. An example scheduling that is based on the example data structure shown in
In step 406, CMTS scheduler 110 utilizes schedule 602 to combine bandwidth requests from the same cable modem 104 to create a single data burst bandwidth for each cable modem 104 (i.e., data provider identifier). This is illustrated in
At this point, data burst bandwidths 702-706 are ready to be granted to their appropriate cable modems as accomplished in step 306 (
As mentioned above, bandwidth requests in this embodiment are scheduled to be serviced based on various quality of service parameters.
In
In step 804, CMTS scheduler 110 schedules each data burst bandwidth based on quality of service parameters. Quality of service parameters include efficiency of transmission and transfer delay tolerance. As stated above, different types of data require different modes of transfer since the importance of timing is different with different types of data. For example, voice data cannot tolerate delays in its transfer. Alternatively, the type of data involved in web surfing can tolerate delays in its transfer.
The priority identifier specified in the request is not significantly important since the cable modem scheduler does not use it 104 when transferring data via the bandwidth. For consistency in all cases is desired, the present invention may specify that the priority identifier of the data burst bandwidth gets the lowest priority that contributes to the accumulated sum. Also note that this embodiment may choice to incorporate scheduling, as shown in
CMTS 102, CMTS scheduler 110 and cable modem scheduler 116 may be implemented using computer 1000 as shown in
The present invention may be implemented using hardware, software or a combination thereof and may be implemented in a computer system or other processing system. In fact, in one embodiment, the invention is directed toward one or more computer systems capable of carrying out the functionality described herein. The computer system 1000 includes one or more processors, such as processor 1004. The processor 1004 is connected to a communication bus 1006. Various software embodiments are described in terms of this example computer system. After reading this description, it will become apparent to a person skilled in the relevant art how to implement the invention using other computer systems and/or computer architectures.
Computer system 1000 also includes a main memory 1008, preferably random access memory (RAM), and can also include a secondary memory 1010. The secondary memory 1010 can include, for example, a hard disk drive 1012 and/or a removable storage drive 1014, representing a floppy disk drive, a magnetic tape drive, an optical disk drive, etc. The removable storage drive 1014 reads from and/or writes to a removable storage unit 1018 in a well known manner. Removable storage unit 1018, represents a floppy disk, magnetic tape, optical disk, etc. which is read by and written to by removable storage drive 1014. As will be appreciated, the removable storage unit 1018 includes a computer usable storage medium having stored therein computer software and/or data.
In alternative embodiments, secondary memory 1010 may include other similar means for allowing computer programs or other instructions to be loaded into computer system 1000. Such means can include, for example, a removable storage unit 1022 and an interface 1020. Examples of such can include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM, or PROM) and associated socket, and other removable storage units 1022 and interfaces 1020 which allow software and data to be transferred from the removable storage unit 1018 to computer system 1000.
Computer system 1000 can also include a communications interface 1024. Communications interface 1024 allows software and data to be transferred between computer system 1000 and external devices. Examples of communications interface 1024 can include a modem, a network interface (such as an Ethernet card), a communications port, a PCMCIA slot and card, etc. Software and data transferred via communications interface 1024 are in the form of signals which can be electronic, electromagnetic, optical or other signals capable of being received by communications interface 1024. These signals 1026 are provided to communications interface via a channel 1028. This channel 1028 carries signals 1026 and can be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link and other communications channels.
In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage device 1018, a hard disk installed in hard disk drive 1012, and signals 1026. These computer program products are means for providing software to computer system 1000.
Computer programs (also called computer control logic) are stored in main memory and/or secondary memory 1010. Computer programs can also be received via communications interface 1024. Such computer programs, when executed, enable the computer system 1000 to perform the features of the present invention as discussed herein. In particular, the computer programs, when executed, enable the processor 1004 to perform the features of the present invention. Accordingly, such computer programs represent controllers of the computer system 1000.
In an embodiment where the invention is implemented using software, the software may be stored in a computer program product and loaded into computer system 1000 using removable storage drive 1014, hard drive 1012 or communications interface 1024. The control logic (software), when executed by the processor 1004, causes the processor 1004 to perform the functions of the invention as described herein.
In another embodiment, the invention is implemented primarily in hardware using, for example, hardware components such as application specific integrated circuits (ASICs). Implementation of the hardware state machine so as to perform the functions described herein will be apparent to persons skilled in the relevant art(s). In yet another embodiment, the invention is implemented using a combination of both hardware and software.
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. This is especially true in light of technology and terms within the relevant art(s) that may be later developed. Thus, the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
Sala, Dolors, Gummalla, Ajay Chandra V.
Patent | Priority | Assignee | Title |
Patent | Priority | Assignee | Title |
4534024, | Dec 02 1982 | Illinois Tool Works Inc | System and method for controlling a multiple access data communications system including both data packets and voice packets being communicated over a cable television system |
4712210, | Sep 07 1984 | Lee Data Corporation | Signal conversion circuit for interconnecting coaxial cable and a twisted pair |
5341374, | Mar 01 1991 | TRILAN SYSTEMS CORPORATION A CORPORATION OF DELAWARE | Communication network integrating voice data and video with distributed call processing |
5421030, | Sep 17 1991 | ARRIS Enterprises, Inc | Communications system and method for bi-directional communications between an upstream control facility and downstream user terminals |
5425027, | Jan 04 1993 | ARRIS Enterprises, Inc | Wide area fiber and TV cable fast packet cell network |
5469495, | May 28 1993 | COMCAST MO GROUP, INC | Method and apparatus for delivering secured telephone service in hybrid coaxial cable network |
5515379, | Oct 18 1993 | Motorola Mobility LLC | Time slot allocation method |
5539449, | May 03 1993 | RPX Corporation | Integrated television services system |
5570355, | Nov 17 1994 | THE CHASE MANHATTAN BANK, AS COLLATERAL AGENT | Method and apparatus enabling synchronous transfer mode and packet mode access for multiple services on a broadband communication network |
5606561, | Jul 28 1995 | Nippon Telegraph and Telephone Corporation | Method, device/microprocessor, and computer software for providing packet fragmentation for fair, efficient downlink transmission with low packet delay |
5631908, | Mar 28 1995 | ENTERASYS NETWORKS, INC | Method and apparatus for generating and implementing smooth schedules for forwarding data flows across cell-based switches |
5742592, | Sep 01 1995 | Google Technology Holdings LLC | Method for communicating data in a wireless communication system |
5742772, | Nov 17 1995 | Alcatel Lucent | Resource management system for a broadband multipoint bridge |
5756280, | Oct 03 1995 | Time Warner Cable Enterprises LLC | Multimedia distribution network including video switch |
5850400, | Apr 27 1995 | NEXT LEVEL COMMUNICATIONS INC | System, method, and apparatus for bidirectional transport of digital data between a digital network and a plurality of devices |
5926478, | Dec 19 1996 | Ericsson Inc | Data transmission over a point-to-multipoint optical network |
5963557, | Apr 11 1997 | Intellectual Ventures II LLC | High capacity reservation multiple access network with multiple shared unidirectional paths |
5982780, | Dec 28 1995 | ADVA OPTICAL NETWORKING LTD | Resource management scheme and arrangement |
6028860, | Oct 23 1996 | ARRIS ENTERPRISES LLC | Prioritized virtual connection transmissions in a packet to ATM cell cable network |
6055268, | May 09 1996 | Texas Instruments Incorporated | Multimode digital modem |
6185224, | Jan 12 1998 | Georgia Tech Research Corporation | System and method for communicating data in a cable network |
6259695, | Jun 11 1998 | SYNCHRODYNE NETWORKS, INC | Packet telephone scheduling with common time reference |
6359901, | Sep 02 1998 | TUMBLEWEED HOLDINGS LLC | Method and apparatus for asynchronous adaptive protocol layer tuning |
6421355, | Jan 20 1998 | Texas Instruments Incorporated | Methods and linecard device for allocating multiple timeslots over digital backplane |
6438630, | Oct 06 1999 | Oracle America, Inc | Scheduling storage accesses for multiple continuous media streams |
6463484, | Jul 09 1999 | PMC-SIERRA, INC | Egress port scheduling using memory efficient request storage |
6546017, | Mar 05 1999 | Cisco Technology, Inc. | Technique for supporting tiers of traffic priority levels in a packet-switched network |
6563829, | Nov 15 1995 | AMERICAN CAPITAL FINANCIAL SERVICES, INC | Method for providing integrated packet services over a shared-media network |
6580730, | Jun 30 1997 | Intel Corporation | Versatile time division multiple access slot assignment unit |
6628609, | Apr 30 1998 | Nortel Networks Limited | Method and apparatus for simple IP-layer bandwidth allocation using ingress control of egress bandwidth |
6724772, | Sep 04 1998 | GLOBALFOUNDRIES Inc | System-on-a-chip with variable bandwidth |
6804251, | Nov 12 1998 | AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LIMITED | System and method for multiplexing data from multiple sources |
6917614, | Sep 17 1999 | ARRIS ENTERPRISES LLC | Multi-channel support for virtual private networks in a packet to ATM cell cable system |
6993007, | Oct 27 1999 | AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LIMITED | System and method for suppressing silence in voice traffic over an asynchronous communication medium |
7061929, | Mar 31 2000 | Oracle America, Inc | Data network with independent transmission channels |
7203164, | Oct 27 1999 | AVAGO TECHNOLOGIES GENERAL IP SINGAPORE PTE LTD | Voice architecture for transmission over a shared, contention based medium |
7219347, | Mar 15 1999 | British Telecommunications public limited company | Resource scheduling |
7237016, | Sep 07 2001 | MICROSEMI SOLUTIONS U S , INC | Method and system to manage resource requests utilizing link-list queues within an arbiter associated with an interconnect device |
7272119, | Nov 02 2000 | Sharp Kabushiki Kaisha | Methods and systems for quality of service in networks comprising wireless devices |
7333495, | Oct 27 1999 | AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LIMITED | Method for scheduling upstream communications |
20010053159, | |||
EP573739, | |||
EP774848, | |||
EP829986, | |||
EP844803, | |||
EP912016, | |||
WO9845678, | |||
WO9918718, | |||
WO9930449, |
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