WO2001097500A1

WO2001097500A1 - Bidding mechanism for determining priority network connections

Info

Publication number: WO2001097500A1
Application number: PCT/US2000/016443
Authority: WO
Inventors: Ichiro Masaki; Ichiro Mizunuma
Original assignee: Mitsubishi Denki Kabushiku Kaisha; Massachusetts Institute Of Technology
Priority date: 2000-06-15
Filing date: 2000-06-15
Publication date: 2001-12-20
Also published as: JP2004503958A

Abstract

A computer network (100) having plurality of user devices (102), connection requesters (105), a connection request message (110) and routers (101). Each router (101) includes connection controller (104). The computer network (100) holds an auction so that users who offer to pay more for a connection and a bit rate on the connection are given priority in obtaining network bandwidth than users who offer less.

Description

Bidding Mechanism for Determining Priority Network Connections

Field of the Invention

The present invention relates generally to the field of communications networks, and more particularly to controlling bit rates and connection times in prioritized cost controlled communications.

Background of the Invention

Many communications networks employ mechanisms to reduce costs. For example, "least cost routing," "automatic route selection, " and "automatic alternative routing"

(LCR/ARS/AAR) mechanisms track carrier's charges and populates routing tables accordingly. The mechanisms can then examine a connection attempt and decide which carrier is the best economic choice for that connection. If the connection fails, then the mechanisms can use a default carrier.

Connections can also be routed according a bidding process between participating carriers, see U.S. Patents 5,606,602 and 5,995,602. There, each carrier informs an auction moderator of the rate it is willing to charge for service between two specific points in the network. The "bid" rate may be lower than the established rate for any of several reasons, e.g., the carrier has excess capacity on that route at that time. The carrier may change its bids as often as it likes during the day as traffic patterns change. The moderator collects the bid information, and transmits it to users. Each user can then select a carrier on a least cost basis.

U.S. Patent 5,371 ,780 describes a bidding mechanism for resource allocation in a cellular network having many fast moving users and a high traffic volume. Resources such as carrier frequencies, time slots, or particular code division multiple access sequences are auctioned to contending users according to a level of priority assigned to each user. The priority level may be based on the quality of service, or a particular needs of a user at the time the user is contending for the resources, for example, the user's request for resources may be prompted by a need to make a handoff.

There, resource allocation includes a bidding period when a determination is made regarding which of a group of contending users has the highest priority level. The allocation then enters an assignment period when an available communications resource is actually assigned to a user having the highest priority level. The bidding and assignment periods are then repeated for the remaining contending users until there are no longer any contending users, or all available resources have been consumed.

In computer networks, such as the Internet, another allocable resource is bandwidth. The bandwidth is the bit rate used for communicating messages. The Internet Engineering Task Force (IETF) Resource reSerVation Protocol (RSVP) allows users to specify a minimum bandwidth they require when establishing a connection. Generally, bandwidths are assigned to connections in "first-come-first-served" order. Thus, situations may arise where a connection cannot be established at a desired bit rate because of bandwidth shortage. In an emergency situation, this could cause serious problems.

Under RSVP, users can establish RSVP connections with a minimum bandwidth guarantee in advance and in anticipation of the need for emergency connections in future. This, however, causes a situation where excess bandwidth is reserved, but not used, unless an emergency should arise. In a worse case scenario, so many users will reserve bandwidth that the required bandwidth constantly exceeds the total bandwidth of the network. Therefore, there is a need to assign network bandwidth to users on something other than a first-come-first-served order. In addition, it is desired to assign bandwidth on a priority basis so that emergency communication can be accommodated in a fair manner. Furthermore, it is desired to establish connections in a predetermined maximum amount of time.

Summary of the Invention

The invention provides a computer network where connections are established and bandwidths are assigned to users according to prices offered by users of the connections. In other words, the network holds an auction where users who offer to pay much more for a connection are given priority in obtaining bandwidths than users who offer less.

The invention has the following advantages. A user who needs to communicate an emergency message can get the required bandwidth at a high priority by offering a higher price even when the network is near full capacity. At the same time, the network can prevent users from reserving bandwidth that remains unused, or from reserving a high bit rate for unimportant usage.

More specially, the invention provides a communication network including user devices and routers connected by communication links. Each source user device includes a connection requester, and each router includes a connection controller. The connection requester generates a connection request message including a minimum bit rate and a unit price and a bidding process. Optionally, the message can also include a maximum time to connect. The connection controller is arranged to establish a connection between the source user source and a destination user device according to the bit rate, the unit price, the bidding process, and optionally the maximum time to connect. The connection requester determines an initial route for the connection and communicates the connection request message to a first router along the route. The connection controller of the router further includes input and output connected by a switch. A memory is configured to store as data a connection management table, one connection time interval table for each output link, and a time interval parameter, and to store as software a connection manager and a plurality of connection agents where there is one connection agent for each connection.

The connection manager registers and deletes records of connections in the connection management table. Each record to includes a plurality of fields including a connection identification unique for each router, a source identification of the source user device, a source user identification, a destination identification of the destination user device, a destination user identification, an input link of the connection, an output link of the connection, a priority indication, the bit rate, and the unit price.

The connection manager initializes records of the connection interval table at the beginning of each update interval T_t. The connection interval table including records with fields, the fields include the connection identification, the unit price, and the bit rate and desired maximum connection time.

When a bit rate B per time interval Tis requested, the router communicates at least n messages per time interval T where n is a minimum integer satisfying a formulation n * (S/T) >= B, where S is the size of each message in bits.

Brief Description of the Drawings

Figure 1 is a block diagram of a network according to the invention; Figure 2 is a block diagram of a router used in the network of Figure 1 ;

Figure 3 is a block diagram of a connection management table maintained in the router of Figure 2;

Figure 4 is a block diagram of a connection interval table of the router of Figure 2; and

Figure 5 is a flow diagram of a process used in a connection agent of the router of Figure 2.

Detailed Description of the Preferred Embodiment System Overview

Figure 1 shows a communication network 100 according to our invention. The network 100 includes a large number of network routers 101 and user devices (UD) 102 connected to each other by network links 103. The network 100 can be the Internet, or other similar public networks, a wireless network, or a private network. As an important characteristic, connections on the network can have allocable bit rates. The user devices can be computers, terminals, or other communication devices such as wireless telephony equipment.

The invention allows users to bid for a minimum bit rate and a maximum amount of time to connect. For example, a user that is planning to receive or transmit a relatively long message, for example, a streamed two-hour video, may be willing to wait five or ten minutes to obtain a high bit rate connection at a lowest possible price. In contrast, a user needing to send a relatively short emergency message maybe willing to pay a premium for getting a connection as soon as possible even if the connection is at a reduced bit rate. According to our invention, each router 101 includes a connection controller 104, and each user device 102 includes a connection requester 105. These are described in greater detail below.

Operational Overview

During operation of the network 100, a user of a source user device can request a connection to a destination user device using the connection requester 102. Specifically, the user of our invention desires a priority connection with a minimum guaranteed bandwidth and/or a maximum amount of time to connect. The minimum bandwidth means that the network will guarantee that the bit rate will not be less than the minimum. The maximum connect time means that the time to connect will not be greater than the maximum. In fact, the user may be willing to offer a premium price for this priority connection. When the user requests such a connection, the source user device generates a connection request message 110. This message includes a minimum bit rate 111 , a unit price 112, an optional maximum time 113, and a bidding process 114.

The bit rate 111 specifies the minimum desired bandwidth for the connection. The unit price 112 is the amount that the users expects or plans to pay for the usage of the connection per unit time. The maximum time 113 specifies the maximum amount of time required to establish the connection, the bidding process 114 defines how to establish the connection according to the expected unit price and the maximum time requirement.

The connection requester 105 can then determine an initial route for the desired connection using known routing tables. The route is a sequence of routers between the source and destination user devices. The connection requester then transmits the connection request message 110 to the first router along the route. Routers Structural Overview

Figure 2 shows a router 200 according to our invention in greater detail. The router 200 includes input links 211 and output links 212. The router also includes a switch 213, e.g., a crossbar or similar switch. These components can be conventional.

The connection controller 104 includes a connection manager 214, a connection management table (CMT) 300, one connection time interval table (CIT) 400 for each output link, a time interval parameter (T) 217, and a plurality of connection agents (A) 218, one for each connection. The tables and parameters can be stored in a memory of the router as data. The manager and agents can also be stored in the memory as software for execution in a processor of the router.

Router Operation

Messages are received into the router 200 via the input links 211. All the connections that pass through the router 200 are registered in the connection management table 300. From there, the messages pass though the switch 213 to the output links 212. The switch references the connection management table to determine which output link should be selected for a particular outgoing message. The router schedules communication of messages in a way that satisfies the parameters in the request message 110.

In other words, if a minimum bandwidth of B bit per time interval Tis requested, then the switch forwards at least n messages per interval T where n is a minimum integer satisfying a formulation n * (S/T) >= B, where S is the size of the message in bits. As shown in Figure 3, the connection manager registers and deletes records of connections in the connection management table 300. Each record 301 includes a number of fields 302. The fields include a connection identification (CID) 311- unique for each router, a source identification (SID) 312 of the source user device, a source user identification (SUID) 313 , a destination identification (DID) 314, a destination user identification (DUID) 315 an input link (IL) 316 and an output link (OL) 317 for the connection, priority indication (P) 317, and a bandwidth (B) 318 and a unit prize ($) the user is offering for the priority connection. The priority indicator indicates whether or not a priority connection according to our invention is to be established. If not, then a conventional connection can be established. The minimum bandwidth field can also store the optional maximum time to connect parameter.

Each connection has an associated connection agent 218. The connection agent is responsible for acquiring the requested bandwidth, perhaps in a shortest possible time. The bandwidth is acquired by negotiating with the connection manager 214. As a result of this negotiation, some connections acquire bandwidths, while other connections may have their bandwidth reduced. The connection manager updates the content of the connection management table 300 according to the result of the negotiations. The updated table is accessed by the switch to determine the input-to-outpύt connection mesh.

The connection manager updates bandwidth allocations in every time interval T. Here, allocation means a distribution of a bandwidth to all connections via a particular output link. Allocation of the bandwidth for a next time interval Tμ₊i) is performed during a previous update time interval T_t, where the interval has a period equal the time interval parameter T 217.

As shown in greater detail in Figure 4, the connection manager initializes the content of the connection interval table 400 at the beginning of each update interval T . The table 400 includes records 401 having fields 402. The fields include a connection identification (CID) -■ 411, aunit price ($) 412, and abandwidth (B) 413 and the optional maximum time to connect. As described below, the records 401 are ordered in decreasing order of unit priceE412.

During each update time interval 7/, each connection agent 218 can register a record for its connection in the connection interval table 400 according to the following registration rules.

Registration Rules 1. A connection agent registers exactly one record for its connection.

2. When registering anew record, or while modifying a registered record, the connection agent arranges the records in the table in a decreasing order of the unit prices.

3. If there is more than one record with the same unit price, then an earlier registered record is ordered before a later registered record.

4. If the total bandwidth of all the records in the table exceeds the total bandwidth available on the output link after registration, or while modification of a record, then the record with the lowest unit price is deleted. Deleting the record of a connection essentially means that the connection now communicates in a traditional non-priority manner. This rule is repeated until the total bandwidth is equal or less than the available bandwidth of the output link. It should be noted that a user experiencing denial or loss of a priority connection can always generate another connection request message, perhaps bidding a higher price. 5. When the time interval T_t completes, the connection manager terminates registration, and the connection management table 300 is updated according to the current content of the connection interval table.

Note, our invention can be worked with any bidding process as long as the above registration rules are enforced.

Bidding Process

Figure 5 shows one possible bidding process 500 that can be used. Other bidding processes can be equally effective.

Step 510 indicates the start of an update time interval T_t. In step 520, a next connection interval table 400 is referenced. In step 530, each connection agent 218 tries to register its connection into the next interval period table, during the update interval T_t according to its bidding process while enforcing the registration rules above. Step 540 terminates registration at the end of the update interval.

Step 550 determines whether or not a connection is registered in the interval table at the end of the update interval T_t.

If registration is successful, the connection agent remains at the router in step 560. Optionally, the connection agent can notify a successful establishment of a connection and the last offered unit price to the following connection agents for the same connection along its route. This notification may depend on the bidding process used by the connection agents. The process can then proceed to the next time interval TM in step 570. If the connection is not registered in the interval table at the end of the update interval T,; in other words, if the agents fails to establish the connection or to keep the connection established, then the connection agent selects to either stay at the router, or try to move to other router in step 580. This can be specified by the user as part of the bidding process.

If the agent selects to stay, the connection agent can optionally notify failure or suspension of the connection to the other connection agents for the same connection along its route in step 560. Whether this notification is needed or not again can depend on the bidding process used by the connection agents.

If the agent selects move to another router, the connection agent sends a "re-trial for other routes" message to the other connection agents for the same connection in its partial route in step 590. Then, the agent starts the process for the re-trial in step 599.

The effect of the invention is to allow users to bid for minimum bit rates and maximum times to connect. Therefore, a user that wants to receive or transmit a relatively long message such as a streamed video, may be willing to wait until a high bit rate connection is obtained at a relatively low price. In contrast, a user that needs to send a short emergency message may well offer a premium price for that privilege. As another effect of the invention, reservation of excess bandwidth is minimized, and the likelihood of exceeding network bandwidth is reduced. In other words, the invention allows the network to operate under open competitive market rules.

Although the invention has been described by way of examples of preferred embodiments, it is to be understood that various other adaptations and modifications may be made within the spirit and scope of the invention. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true spirit and scope of the invention.

Claims

ClaimsWe claim:

1. A communication network including a plurality of user devices and routers connected to each other by communication links, comprising: a connection requester in a source user device, the connection requester to generate a connection request message including a minimum bit rate and a unit price and a bidding process; a connection controller in a router, the connection controller arranged to establish a connection between the source user source and a destination user device according to the bit rate, the unit price, and the bidding process.

2. The communication network of claim 1 wherein the connection request message further includes a maximum time, and the connection controller establishes the connection according the maximum connection time.

3. The communication network of claim 1 wherein the connection requester determines an initial route for the connection and communicates the connection request message to a first router along the route.

4. The communication network of claim 1 wherein the router further comprises: a plurality of input links where one of the input links connects to the source user device; a plurality of output links where one of the output links connects to the destination user device; and a switch connecting the input links to the output links.

5. The communication network of claim 1 wherein the connection controller further comprises: a memory configured to store as data a connection management table, one connection time interval table for each output link, and a time interval parameter, and to store as software a connection manager and a plurality of connection agents where there is one connection agent for each connection.

6. The communication network of claim 5 wherein the connection manager registers and deletes records of connections in the connection management table, each record to includes a plurality of fields includes a connection identification unique for each router, a source identification of the source user device, a source user identification, a destination identification of the destination user device, a destination user identification, an input link of the connection, an output link of the connection, a priority indication, the bit rate, and the unit price.

7. The communication network of claim 5 wherein the connection manager initializes records of the connection interval table at the beginning of each update interval T_t.

8. The communication network of claim 5 wherein the connection interval table includes a plurality of fields, the fields including the connection identification, the unit price, and the bit rate.

9. The communication network of claim 5 where the bit rate B per time interval Tis requested so that the router communicates at least n messages per time interval T where n is a minimum integer satisfying a formulation n * (S/T) >= B, where S is the size of each message in bits.

10. The communication network of claim 9 wherein each connection agent registers exactly one record for a connection in the connection interval table during the time interval T, and the records in the connection interval table are arranges in a decreasing order of the unit prices, and if there is more than one record with the same unit price, then an earlier registered record is ordered before a later registered record, and if the total bit rate all the records in the connection interval table exceeds the total bit rate available on an associated output link after registration or while modification of a record, then the record with a lowest unit price is deleted from the connection interval table.

11. The communication network of claim 10 wherein the connection manager updates the connection management table at the end of the time interval T according to the connection interval tables.

12. A method for establishing connections in a communication network, the communication network including a plurality of user devices and routers connected by communication links, comprising: generating a connection request message including a minimum bit rate and a unit price and a bidding process in a connection requester of source user device; establishing a connection between the source user source and a destination user device according to the bit rate, the unit price, and the bidding process in a connection controller of a router.

13. The method of claim 12 wherein the connection request message further includes a maximum time, and the connection controller establishes the connection according the maximum connection time.

14. The method of claim 12 wherein the connection requester determines an initial route for the connection and communicates the connection request message to a first router along the route.

15. The method of claim 12 wherein the router further comprises: connecting a plurality of input links to a plurality of output links via a switch.

16. The method of claim 12 wherein the connection controller includes a memory, and further comprising: storing a connection management table, one connection time interval table for each output link, and a time interval parameter as data; and storing a connection manager and a plurality of connection agents, one for each connection, as software in the memory.

17. The method of claim 16 wherein the connection manager registers and deletes records of connections in the connection management table, each record to includes a plurality of fields includes a connection identification unique for each router, a source identification of the source user device, a source user identification, a destination identification of the destination user device, a destination user identification, an input link of the connection, an output link of the connection, a priority indication, the bit rate, and the unit price.

18. The method of claim 16 wherein the connection manager initializes records of the connection interval table at the beginning of each update interval T,.

19. The method of claim 16 wherein the connection interval table includes aplurality of fields, the fields including the connection identification, the unit price, and the bit rate.

20. The method of claim 16 wherein the bit rate B per time interval T is requested so that the router communicates at least n messages per time interval T where n is a minimum integer satisfying a formulation n * (S/T) >= B, where S is the size of each message in bits.

21. The method of claim 16 further comprising: registering exactly one record for a connection in the connection interval table during the time interval -T; arranging the records in the connection interval table arranges in a decreasing order of the unit prices, if there is more than one record with the same unit price, then an earlier registered record is ordered before a later registered record, and if the total bit rate all the records in the connection interval table exceeds the total bit rate available on an associated output link after registration or while modification of a record, then the record with a lowest unit price is deleted from the connection interval table.

22. The method of claim 21 wherein the connection manager updates the connection management table at the end of the time interval T according to the connection interval tables.