A system and method for providing data services using idle cell resources

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DESCRIPTION

System and procedure for the provision of data services using inactive cellular resources.

Field of the invention

This invention relates generally to a switched communication system and more particularly to a method for transmitting data using the free resources of a communication system. Background of the invention

Circuit switched networks, such as cellular communication systems, generally offer a single class of service that is used primarily for voice calls. In a cellular communication system, voice calls compete with data calls for the same limited number of channels available in a particular cell or network access point. Consequently, service providers cannot justify different rates for data calls and voice calls, and as a consequence cellular communication systems have not been used extensively as data networks.

Some service providers have considered solving the problem of having a single class of service by deploying separate facilities to handle data calls at lower speeds. Separate facilities for data in a cellular communication system reduce the cost of data calls, but only in that the capital investment for such facilities is less than that of cellular communication systems used for voice calls. Consequently, in current cellular communication systems, the demand for the voice call service is what sets the price that the company can rationally charge to compete in the data call service. European Patent Application 370,826 describes a protocol for a simplex communication system that is responsible for notifying a subscriber's apparatus that its predetermined time quota is expiring. US Patent No. 5,574,977 describes a system and method for providing reserved channels and / or queue positions to priority users during periods of call congestion. European Application 717,579 describes a system for prioritizing service to users of a cellular telephone system.

Summary of the invention

The present invention offers a multilevel service in a cellular wireless communication system, as well as in a switched cable communication network, by providing a system and a method that uses the free channels of an existing cellular communication system for transmission. of data. By offering various levels of service over free channels, the service provider can rationally rate the data call service below the rate level of the voice call service, while increasing the use of the cellular communication system.

In particular, the system and method of the present invention are based on the fact that many data transmission applications are not particularly time sensitive. In contrast, voice calls are time sensitive and require immediate connection and continuity of connection. A delay of several minutes or even several hours in sending an email does not substantially diminish the opinion that the user has about the data transmission service. Similarly, an interruption in the sending of an email will not substantially lower the opinion about the service. Therefore, data calls, unlike voice calls, can wait for the availability of a free dog . By using free channels for data transmission, the service provider can rationally rate data calls at a lower price than voice calls, which have higher priority. The use of free channel capacity for data calls at a lower price also ensures greater utilization of the cellular communication system.

In order to use free channels for data transmission, the system and method of the present invention assign a priority to the apparatus of each remote user. The device priority of each remote user is part of the information about the profile and authorization of each remote user. The priority is associated with the Mobile Identification Number (MIN) of each remote user. The profile and authorization information including priority is kept in a database (home position record (HLR)) existing on the mobile switch. The mobile switch controls the cellular communication system and provides the computerized intelligence for the present invention.

When a service call request is received at the mobile switch, either from a remote user or to a remote user (first remote user), the mobile switch first checks the information about the profile and authorization of the first remote user, which is stored in the database (HLR) and determines the priority of the remote user. The mobile switch then checks whether the cell (or cell sector) in which the apparatus of the first remote user is located has any free channels. If there is any free channel, the call to or from the device of the first remote user is immediately connected regardless of the priority of the device of the first remote user.

However, if there is no free channel to connect the call to or from the device of the first remote user, the mobile switch searches the cell for a channel that is being used by the device of a remote user with a lower priority than the device priority of the first remote user. If the device of a remote user with a lower priority is not found on any active channel, the call request of the device of the first remote user can be queued, ordered by priority, with other remote users waiting for the availability of a free channel . When the remote user is queued, the mobile switch notifies the remote user that he has been queued so that the remote user does not continue to request service while the remote user's service request is in the queue. When a channel becomes free, the remote user located at the head of the ordered queue is connected. Whether or not a remote user is queued depends on a number of factors including the profile and authorization information that exists in the HLR database for the remote user, whether the call is inbound or outbound, and of how the input data was handled by the

ES 2 235 348 T3 mobile switch. If the remote user is not registered to be queued or if queuing would paralyze other resources, his call request will be cut off when he cannot be quickly connected.

However, if the device of a lower priority remote user (second remote user) appears in the cell (or cell sector), the mobile switch will interrupt the call of the device of the second remote user and connect the call of the device of the first remote user on vacant channel. If more than one lower priority remote user apparatus appears in the cell, and if both lower priority users have the same priority, the lower priority user with the longest call duration will be interrupted in favor of the call request from the device of the first remote user.

By interrupting the call of the second remote user in favor of the first remote user, the data transmission software of the second remote user recognizes the interruption and stores the parameters that will allow the second remote user's data transmission to resume at the point where it was produced the interruption of the transmission. After the call from the second remote user's handset is interrupted, a request to resume the call from the second remote user's handset may be placed in the priority queue to await the availability of a free channel. When the second remote user is placed in the ordered queue, the mobile switch notifies the second remote user not to attempt to reestablish the connection until their call request reaches the head of the ordered queue. By notifying the second remote user of the call interruption and queuing, the second remote user is also given the opportunity to cut off their data transmission in an orderly fashion. When the interrupted call from the second remote user reaches the head of the ordered queue and when a free channel is available, the call resumes at the point where it was interrupted.

When the call request to the first remote user originates in the public switched communications network and is for the transmission of data to the first remote user, the mobile switch retrieves from the HLR database the information about the profile and authorization of the first remote user. If the first remote user is a high priority data user with time sensitive data (such as video data associated with a video conference call), the request will be connected based on its priority, and the connection will be maintained for the duration Of the call.

However, if the first remote user is a low priority data appliance and if the data is not time sensitive, the mobile switch will store all incoming data from the public switched communications network and disconnect the call from the network. public switched communications network once you have stored the input data. Before the user who called over the public switched communications network, the call appears to have been immediately connected and completed, so that said calling user will not request service for that particular incoming call. In fact, the data is stored in a memory of the mobile switch, or in another central position, and a call request to the first remote user is generated in the mobile switch. If a free channel is available, the first remote user is connected, and data from memory is delivered (sent) to the first remote user. If no free channel is immediately available, the call request for the first remote user is queued, and the data is delivered (sent) from memory to the first remote user's set when the first remote user reaches the station. head of the queue in order and when a free channel is available.

In another aspect of the present invention, a multi-channel data service is provided using a mix of priorities. For example, a three-channel data service will be provided for a remote user by assigning a high priority to one of the remote user's channels and a low priority to the other two channels. This mix of priority assignments allows the remote user to always obtain on the high priority channel a high priority access equal to that of a voice call. Outside of peak hours, when free channels are available for lower priority data, the remote user will be able to communicate on all three channels at approximately three times the speed of speech.

The system and method of the present invention allows an existing cellular communication system or a switched communication network to establish calls based on the priority assigned to each remote user. A call to or from a lower priority remote user, such as a data call, is only connected after the higher priority calls, such as voice calls, have been completed and free channels become available. By prioritizing and using free channels for lower priority calls, a service provider can rationally offer lower rates on lower priority calls while increasing overall utilization of the cellular communication system.

Brief description of the drawings

Figure 1 is a block diagram of a cellular communication system that constitutes the environment for the present invention.

Figure 2 is a flow chart illustrating the procedure for handling service requests from a remote user in accordance with the present invention.

Figures 3A and 3B are a flow chart illustrating the procedure for handling requests to serve a remote user by transmitting data to the remote user in accordance with the present invention. Detailed description

One of the environments for the present invention is an existing cellular communication system. Such cellular communication systems include among others those built and operated according to various well-known standards, such as TDMA (IS-54 and IS-136), AMPS (IS-41), NAMPS, GSM, DCS1800, DCS1900, CDMA (IS- 95), PACS, TACS, JTACS, and PDC. The present invention is also applicable to any other switched communication network that has a control switch and an access point per controlled node with a limited number of channels in each node, such as digital bearer networks in a loop.

Turning to the drawings in which the same numbers refer to the same parts or stages in the various figures, Figure 1 of this technical specification

ES 2 235 348 T3 is a schematic diagram of a cellular communication system 10 that constitutes an environment for the present invention. The cellular communication system 10 comprises a mobile switch 14 and a number of cells, such as the illustrated cell 22. The cellular communication system 10 is connected to the public switched telecommunications system 12 through the mobile switch 14.

Each cell, such as cell 22, has a transmission / reception tower 24 that transmits data and receives data from remote users 26 (mobile 1), 28 (mobile 2), and 30 (mobile 3). Each cell has a limited number of channels over which data can be transmitted and received. Although each remote user 26, 28, and 30 is represented as an automobile-based telephone user, remote users can include a variety of devices such as mobile phones, fax machines, computers, telemetry devices, and control devices, among others. others.

The mobile switch 14 comprises a buffer 16, a cell controller 18, and a home position register (HLR) 20. The cell controller 18 is a high-speed general purpose digital computer programmed to control the functions required by the switch. 14 from mobiles. The HLR 20 is a memory device capable of storing a database under the control of the cell controller 18. The HLR database 20 includes the profile and authorization information including the priority of each of the remote users. Buffer 16 is a memory device under the control of cell controller 18 that is used to receive and store data for later delivery to a remote user of the cell in accordance with one aspect of the present invention. Although buffer 16 is represented within mobile switch 14, it could also be remotely located.

In the cellular communication system 10, the voice call service requires immediate access to a channel and continuity of connection on the channel for the duration of the voice call. Remote users will consider a voice call service unacceptable if a remote user cannot access a channel quickly and / or if the voice call is dropped during a conversation. On the contrary, the data call service does not require the same instantaneous access or continuity of connection. An e-mail message or a fax document can be delayed for several minutes or even hours without adversely affecting the usability of the data call service. Similarly, the transmission of an e-mail message or a facsimile document can be interrupted and then resumed without adversely affecting service as long as the resumption can resume transmission at the point of interruption.

The present invention provides a system and method for taking advantage of the different priorities required for successful voice calls and data calls. To provide different priorities of service, each remote user's appliance is assigned a priority based on the nature of use of that remote user's appliance. The priority assignment to each user is associated with the user's mobile identification number (MIN). The priorities associated with the MIN of each user are stored in the HLR database 20 existing in the mobile switch 14. For example, mobile phones, which provide a voice call service, are assigned the highest priority. On the other hand, wireless fax machines and wireless email systems are assigned a lower priority.

Although the present invention will be described in relation to a two priority system, high priority for voice and low priority for data, the invention lends itself to multiple priorities. Each low priority level allows the service provider the opportunity to offer lower rates to customers with low priority data transmission needs. In contrast, the high priority service allows the service provider to rationally offer a higher rate.

In addition, a remote user apparatus could be assigned multiple MINs, each with a different priority or a mix of priorities. Such apparatuses with multiple MINs could thus provide, for example, three service channels, one high priority service channel and two additional lower priority data service channels. Such a device would have high priority access for data transmission at all times, and outside peak hours it could use all three channels to increase the data transmission speed by using all three channels together.

Turning to Figure 2, a flow chart showing the procedure of the present invention is shown when remote user 26 (mobile 1) requests service from cell 22. The procedure of the present invention begins in step 200 with a request service by mobile 1 of cell 22. The service request is transmitted in a conventional way to the mobile switch 14.

In step 204 the cell controller 18 interrogates the HLR database 20 to know the service priority of mobile 1 based on the profile and authorization information of mobile 1. The profile and authorization information of mobile 1 was supplied to the mobile switch 14 when the mobile 1 first registered with the service provider of the cellular communication system 10. After acquiring the profile and authorization information including the priority of mobile 1 from the HLR in step 204, the procedure proceeds to step 202.

In step 202 the cell controller 18 of the mobile switch 14 checks if a free channel is available to service the service request of mobile 1. If in step 202 the cell controller 18 of the mobile switch 14 determines that there is a free channel in cell 22, the procedure follows the "yes" branch until step 216, and the free channel is assigned to mobile 1 regardless of the priority of mobile 1. When the call from mobile 1 ends, the procedure goes to step 222 in which the terminated call from mobile is interrupted

1.

If, on the other hand, in step 202 no free channel is available, the procedure follows the "no" branch from step 202 to step 206. In step 206 the procedure determines whether there is a remote user in cell 22 in progress that has a priority lower than the priority of mobile 1. If all users have a priority equal to or higher than the priority of mobile 1, the procedure follows the "no" branch until step 220.

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In step 220, based on mobile 1's profile and authorization information, cell controller 18 decides whether mobile 1's call request should be queued for subsequent connection. If the profile and authorization information of mobile 1 does not authorize the queuing, the procedure follows the "no" branch until step 224, in which the call request of mobile 1 is terminated. Mobile 1 may not want its call request to be queued if, for example, mobile 1 is a low priority voice service. This low priority voice user already knows that from time to time he will not have access to the network, but such a voice user probably does not want to wait in a queue of indeterminate length. In contrast, such a low priority voice user will simply want to make the call later.

On the other hand, if mobile 1 has a low priority data service, this data user may want to queue his call for a later service. If the cell controller 18 determines in step 220 that mobile 1 is registered with the service provider to be queued, the procedure follows the "yes" branch to step 208. In step 208 the request for Mobile 1 call in a queue to wait for the next available channel in cell 22. In step 208 the cell controller also notifies the mobile 1 that its call request has been queued, so that the mobile 1 does not continue to send new call requests to the mobile switch 14. In step 210 the queue is ordered by priorities and waiting times, so that the call request with the highest priority and longest waiting time is at the head of the queue and is assigned the next available channel in cell 22 . After ordering the queue in step 210, the procedure returns to step 202 to search for the next available channel in cell 22 for the call request from the remote user at the head of the queue.

However, if in step 206 the cell controller 18 determines that a channel of cell 22 is being used by a remote user, such as mobile 2, with a lower priority than mobile 1, the procedure follows the "yes" branch. "To step 212. At step 212 the cell controller 18 drops the low priority data call from mobile 2, and at step 216 the cell controller 18 allocates the vacant channel to mobile 1. The mobile 1 call is completed and ended in step 222.

The selection of mobile 2 to interrupt the call in step 212 is based on the priority of mobile 2 and the duration of the call of mobile 2 at the time of interruption. For example, if several remote users in progress have the same priority as mobile 2, whose priority is lower than mobile 1, the cell controller 18 will interrupt the remote user who has been connected the longest. In this case, it is assumed that mobile 2 has the longest call among those users who have the same priority as mobile 2. As part of the interruption process of mobile 2, the software that controls the transmission of data to and from the Mobile 2 will recognize the interruption and mark the point in the transmission at which the call was interrupted. When the call to mobile 2 resumes, the software will be able to recover the data transfer at the point of interruption.

Once the call of mobile 2 is interrupted in step 212, the procedure advances to step 218 in which, based on the profile and authorization information of mobile 2, the cell controller 18 decides whether a request from mobile 2 to the resumption of your call will need to be queued. If the profile and authorization information of mobile 2 does not authorize the queuing, the procedure follows the "no" branch from step 218 to step 224, in which the request to resume the call of mobile 2 is completed. Alternatively, the procedure follows the "yes" branch from step 218 to step 214, in which cell controller 18 queues a request to resume the interrupted call from mobile 2. In step 214 the cell controller 18 also notifies the mobile 2 that its call has been queued, so that the mobile 2 does not attempt to re-establish its call by means of new call requests to the mobile switch 14. The queue is ordered in step 210 as described above, and the queued call requests wait for the next available channel in cell 22 as indicated by the return path to step 202.

If the interrupted call from mobile 2 was transferring data to mobile 2 at the time of the interruption, the cell controller 18 can maintain the connection with the public switched telephone network 12 to resume the data transfer when the call to mobile 2 is awarded to a free channel. Alternatively, cell control 18 can store in buffer 16 all data from the caller, drop the call from the public switched telephone network 12, and transfer the data from buffer 16 to mobile 2 when a call is re-allocated. free channel to mobile

two. Such data storage and sending will be described in greater detail in relation to Figure 3. If, on the contrary, the interrupted call from mobile 2 was transferring data from mobile 2 to a user of the public switched telephone network 12, the controller 18 of Cells will maintain the connection with the public switched telephone network 12 until a channel is reallocated for mobile 2 and the transmission is completed.

Turning to Figures 3A and 3B, a flow chart showing the method of the present invention is represented when a user of the public switched telephone network 12 requests a service from the remote user 26 (mobile 1) of cell 22. The method of the present invention begins in step 300 with a service request from the public switched telephone network 12 for a call to mobile 1 of cell 22. The service request to mobile 1 is transmitted from public switched telephone network 12 to mobile switch 14. After receiving the call request in step 300, the procedure proceeds to step 304.

In step 304 the cell controller 18 searches the HLR database 20 to determine the service priority of mobile 1 based on the profile and authorization information of mobile 1's MIN. Based on the priority of mobile 1, cell controller 18 determines in step 301 whether the call is a data transfer call. If at step 301 the cell controller 18 determines that the call is not a data transfer call, the procedure follows the "no" branch until step 302 (Figure 3B).

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If in step 301 the cell controller 18 determines that the call is a data transfer call, the procedure follows the "yes" branch to step 303. In step 303 the cell controller 18 determines whether the data should be stored in the buffer 16. The decision to store the data or not in step 303 is based on the estimate made by the cell controller about the waiting time until a connection can be made with mobile 1. If the data is not stored, the procedure follows the "no" branch until step 302 (Figure 3B) and retains the connection with the incoming call from the public switched telecommunications network 12. If the data is stored in step 303, the procedure follows the "yes" branch until step 307.

In step 307 the incoming data from the public switched telephone network 12 is stored in buffer 16, and the connection to the public switched telephone network is interrupted. The use of buffer 16 and step 307 is optional, and the mobile switch 14 could simply maintain the connection to the public switched telephone network until the data transmission to mobile 1 is completed. After storing the data in buffer 16 at step 307, the procedure proceeds to step 302 (Figure 3B).

In step 302, the cell controller 18 of the mobile switch 14 checks if a free channel is available to service the call request to mobile 1. If there is a free channel in cell 22, the procedure follows the "yes" branch. "Until step 316, and a free channel is allocated to mobile 1 regardless of the priority of mobile 1. When the call to mobile 1 has been completed, the procedure proceeds to step 322, in which the call to mobile 1 is dropped and the data in the buffer for mobile 1 is flushed (marked for overwrite).

If no free channel is available, the procedure follows the "no" branch until step 306. In step 306 the procedure determines if there is in cell 22 any remote user in progress that has a lower priority than the priority of mobile 1 If all users have a priority equal to or higher than the priority of mobile 1, the procedure follows the "no" branch until step 320. In step 320 the cell controller determines from the profile and authorization information of mobile 1 and from the handling of the incoming data whether the call request to mobile 1 should be queued. If the incoming data was not stored in step 307 (Figure 3A), the call request to mobile 1 cannot be queued, and the procedure follows the "no" branch until step 324 in which the request is terminated. of the incoming call, and the user of the incoming call is notified that the connection with mobile 1 was not made. If the incoming data was stored in step 307 (Figure 3A) then the call request to mobile 1 will be queued by cell controller 18, and the procedure will follow the "yes" branch until step 308.

In step 308 the call request to mobile 1 is queued ordered, and mobile 1 is notified that it has an incoming call request queued waiting for the next available channel in cell 22. In step 310 the queue is ordered by priority and wait times, so that the call request with the highest priority and longest wait time is put at the head of the queue to be assigned to the next available channel in cell 22. After ordering the queue in step 310, the procedure returns to step 302 to search for the next available channel in cell 22 for the call request located at the head of the ordered queue.

However, if in step 306 the cell controller 18 determines that a channel of cell 22 is being used by a remote user, such as mobile 2, with a lower priority than mobile 1, the procedure follows the "yes" branch. "To step 312. At step 312 cell controller 18 drops the lowest priority data call from mobile 2, and at step 316 allocates the vacant channel to mobile 1. The selection of mobile 2 for the call interruption is based on the priority of mobile 2 and the duration of the call of mobile 2 at the time of interruption. As part of the interruption process for mobile 2, the software that controls the transmission of data to and from mobile 2 will recognize the interruption and mark the point in the transmission at which the call was interrupted. When the call to mobile 2 resumes, the software will recover the data transfer at the point of interruption.

Once the call of mobile 2 is interrupted in step 312, the procedure proceeds to step 318 in which the cell controller 18 determines whether the request of mobile 2 to resume its connection should be queued or terminated. If the request to resume the call is to be terminated, the procedure follows the "no" branch until step 324 in which the cell controller 18 terminates the request from mobile 2 to resume its interrupted call. Alternatively, the procedure follows the "yes" branch from step 318 to step 314, in which cell controller 18 queues mobile 2's request to resume its interrupted call and notifies mobile 2 that its request resume has been queued. The queue is sorted in step 310, and the queued call requests wait for the next available channel in cell 22 for the call request at the head of the queue sorted as indicated by the return path to step 302 .

Based on the foregoing, it should be appreciated that the present invention also contemplates multiple priorities for multiple levels of service. For example, voice calls could have multiple levels to distinguish emergency services from other voice calls. Within a low priority level, data transmissions could be subdivided, for example, to give a higher priority to a facsimile transmission than to an e-mail. Furthermore the emails could also be subdivided to provide higher and lower levels of priority of service. Each priority could have a different speed. The ordering of the queue at the mobile switch 14 ensures that the various service requests for each handset run their course in the proper order of priority as free channels become available.