Abstract:
A communication system monitors the resources that are available for new users. When the availability of free resources becomes too small or falls below a threshold, the communication system initiates a reduction in the the class of service to selected users. The class of service can be reduced by reducing the quality of service provided to existing communications or by providing selected new users with only lower quality communications. The decision to alter the class of service is alerted to the end user and based on the profile of the end user, appropriate alteration of a specific resource parameter is undertaken. The quality of communications may be reduced, for example, by decreasing the information carrying capacity of the channel available to a particular user and thereby decreasing the data transfer rate, decreasing the amount of error encoding used to detect and correct errors introduced by a communication channel, or in the case of a wireless system, using a lower rate vocoder (voice encoder) which win reduce the voice quality or clarity of the speech transmitted over the communication channel.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to telecommunications; more particularly, to the reallocation of network resources. 
     2. Description of the Related Art 
     Communication systems have a finite number of resources. Those resources include, for example, equipment, fibers, conductors, signal processors, and radio frequency spectrum. The amount of available capacity in a communication network varies with the number of users. When a large number of users are utilizing the network, there may be insufficient network resources to support new users. Additionally, the amount of available capacity varies as equipment is taken offline for maintenance or repair. Presently, when there are insufficient resources to support new callers or users, the new user is refused service which results in user annoyance and dissatisfaction. 
     SUMMARY OF THE INVENTION 
     The present invention solves the aforementioned problems by varying the class of service to existing users. The class of service is varied by changing, for example, speech clarity, data transfer rate or error correction capability. Downgrading a class of service for existing users frees up communication network resources for new users. This avoids frustrating new users who are attempting to start new calls. Additionally, users on existing calls are not dissatisfied by a decrease in the class of service because they have previously agreed to accept downgrades and receive a price discount for the decreased service. It is also possible for users to refuse a downgrade in service in real-time. For example, while a call is in progress the user is given an opportunity to refuse the communication system&#39;s request to downgrade the call&#39;s class of service. Callers who have this right of refusal receive a more modest price discount than users who unconditionally accept service downgrades. 
     The communication system monitors the resources that are available for new users. When the availability of resources becomes too small or falls below a predetermined threshold, the communication system initiates a reduction in the the class of service to selected users. The class of service can be reduced by reducing the quality of service provided to existing communications or by providing the new users with only lower quality communications. The quality of communications may be reduced, for example, by decreasing the number of channels made available to a particular user and thereby decreasing the data transfer rate, decreasing the amount of error encoding used to detect and correct errors introduced by a communication channel, or in the case of a wireless system, using a lower rate vocoder (voice encoder) which will reduce the voice quality or clarity of the speech transmitted over the communication channel. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1A and 1B illustrate available communication systems resources; 
     FIGS. 2A,  2 B and  2 C illustrate the contents of a database used to identify a user for a change in service class; 
     FIG. 3 is a block diagram of a wireless communication system; 
     FIG. 4 illustrates a protocol or messaging sequence for dynamically varying the class of service provided to a user; 
     FIG. 5 illustrates a communication path passing through several different networks; 
     FIG. 6 illustrates several networks with access to a common variable class of service database(s); 
     FIG. 7 illustrates a portion of a wireless network; 
     FIG. 8 illustrates a portion of a communication network; and 
     FIG. 9 illustrates a portion of the internet and an internet service provider. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1A and 1B illustrate the available resources in a communication system. FIG. 1A illustrates a situation where 90 percent of the communication system or network resources are being utilized by X users. This leaves only 10 percent of the system&#39;s resources available for new calls or service requests. In this situation, the communication system may quickly become overloaded and will be unable to serve new users. 
     FIG. 1B illustrates the situation where the class of service provided to at least some of the X number of users has been decreased. As a result of downgrading the class of service, additional system resources have been made available for new users. In this example, the amount of system resources used by current calls has been decreased from 90 to 75 percent and thereby provides 25 percent of the communication system resources for new users. It should be noted that by downgrading the class or quality of service provided to some of the users, additional resources have been made available for other users. As a result, new users will not be frustrated by being unable to receive services, and the users who have received a decrease in service quality will be compensated by receiving a lower charge for their communication services. 
     FIGS. 2A,  2 B and  2 C illustrate several entries in a database that are used to select users who may receive a downgrade or decrease in service class. It should be noted that separate tables or databases may be used for different types of communications. In this example, table  14  is used for voice communications, table  16  is used for data and table  18  is used for video. In reference to table  16 , column  20  is used for Caller ID. The Caller ID may simply be a user&#39;s telephone or terminal number or another identifier. Column  22  contains entries for each user which indicates the initial class of service that a user receives when starting a call (assuming sufficient system resources are available). If the resources are available, the user is given the best option in each of the communication characteristics in columns  24 ,  26 , and  28 . Users with a higher initial class of service have more desirable options associated with one or more communication characteristics. There can be any number of classes, but for simplicity, we will only discuss three classes in this example. Premium class refers to the best class of service where, for example, a user is given a high data transfer rate over the communication network and a low error rate. The high rate of transmission may be provided, for example, by using multiple communication channels in parallel. The low error rate is provided by using more sophisticated error encoding techniques where extra bits of information are sent so that errors can be detected and corrected. Standard class service is of lower quality when compared to premium class. Standard class, for example, provides the user with a lower transmission rate and/or a higher error rate than premium class. Economy class service, which is the lowest class in this example, provides the user with the lowest transmission rate and/or the highest error rate. 
     In reference to table  16 , columns  24 ,  26 , and  28  list options or arrangements of options for different service characteristics. Column  24  lists data transfer rate options in terms of the number of channels that are provided to a user for communications. The larger number of channels; the higher the data transfer rate. Column  26  lists the channel type options as analog or digital where digital typically provides better performance. Column  28  indicates error rate options as ranges of error rates. Column  30  illustrates a user&#39;s priority level. The user with the highest priority level will be the last to receive a decrease in service class and users with the lowest priorities will be the first to receive a decrease in service class. Additionally, user&#39;s with the highest priority level will be the first to receive a class of service upgrade when additional system resources become available. Column  32  indicates whether a user has the right to refuse a decrease in service class. Callers who have a right to refuse a decrease in service class may be charged extra for that right and/or each time they exercise that right. Column  34  indicates whether a user is ever willing to take a downgrade. Column  36  indicates the current status of the user. This column indicates which option for each of the possible communication characteristics are being provided to a particular user. Knowing the current status of the users helps to prevent providing multiple downgrades to a single user without downgrading other users who have not received their first downgrade. 
     Rows  40 ,  42  and  44  of table  16  indicate the status and options available for three different users. The user associated with row  40  is a premium class customer as indicated by column  22 , and is willing to take downgrades but does not have a right to refuse as indicated by columns  34  and  32 , respectively. This user has the highest priority and therefore is in the last group to receive a downgrade and the first to receive an upgrade. Current status is listed in column  36 , which indicates that the user now has access to three channels, all of which are digital, and has an error rate of 0.1%. Column  24  indicates that the user is willing to accept a downgrade from three channels to only one or two channels. Column  26  indicates that the user is wiling to take a downgrade from a digital to an analog channel, and column  28  indicates the user is willing to accept a downgrade in error rates from 0.1% to a maximum error rate of 0.5%. Rows  42  and  44  similarly indicate the type of service options that are available for other users and the current status of those users. 
     Tables  14  and  18  indicate the types of downgrades that are available for voice and video communications, respectively. They are similar to the tables associated with data calls except that different communication service characteristics are changed when downgrading or upgrading the class of service. With regard to voice and in reference to table  14 , channel types and error rates may be modified as described with regard to data communications; however, voice communications are also provided with vocoder options. Vocoders are used to encode speech for wireless communication. 13K vocoders provide the clearest speech while EVRC (enhanced variable rate coders) and 4K vocoders provide less clear speech while the 4K vocoder is the least clear. Table  18  illustrates communication channel characteristics that may be modified to vary the class of service for video communications. As discussed earlier, rate options, channel type options, and error rate options may be varied, but in the case of video, encoding options may also be varied. For example, encoding options may include choosing between MPEG1 and MPEG2 encoding (MPEG 1 and MPEG 2 are standard video encoding techniques), where MPEG2 provides superior performance. 
     It should be noted that the downgrades that are carried out in accordance with the database illustrated by FIG. 2 may be carried out dynamically, that is, during a call, or they may be carried out at the beginning of a call. Additionally, other call types, communication characteristics and options may be used to produce the tables of FIGS. 2A,  2 B and  2 C. 
     FIG. 3 illustrates a typical wireless telecommunication system. The system consists of mobile switching centers (MSC)  80  and MSC  82 . MSC  80  serves base stations  84  and  86 . MSC  82  serves base stations  88  and  90 . The MSCs communicate with the public switched telephone network (PSTN)  92 . PSTN  92  then provides a communication link to, for example, a local exchange carrier (LEC)  94  which then provides communication to an end terminal  96 . Each base station provides wireless communications within a geographic area surrounding the base station. In this example, assume that base station  84  provides telecommunication services within circle  98 . As a result, base station  84  provides telecommunication services to mobile stations  100  and  102  and any other mobile stations that may be within circle  98 . 
     Each of mobile switching centers  82  and  80  is in communication with database  106 . Database  106  contains the information discussed with regard to FIGS. 2A,  2 B and  2 C. Mobile switching center  82  communicates with database  106  over communication link  108  and mobile switching center  80  communicates with database  106  over communication link  110 . Communication links  108  and  110  may be direct links or may be through a PSTN or other type of network such as a data network or an ATM (asynchronous transfer mode) network. When one of the base stations or mobile switching centers detects a shortage in network resources, database  106  is accessed to determine which calls may be downgraded, what downgrades are available, and the current status of the users. 
     In the example that will be discussed in reference to FIG. 4, it is assumed that there are a large number of mobile stations within circle  98  of FIG. 3 so that resources of base station  84  are ninety percent utilized. As a result, it is necessary to decrease the class of service to one or more users within circle  98 . FIG. 4 illustrates the communication protocol or exchange of messages between base station  84  and the mobile station that will have its class of service downgraded. In step  120 , base station  84  detects a potential system or resource overload. It then executes step  122  where it accesses database  106  to identify or select a user for downgrading. The user is selected based on the communication characteristic that will help alleviate the network resource overload, and on the user with the lowest priority that has not already been downgraded. Another option for downgrade may be based on home versus visitor/roamer status. In this example, the user of row  112  of FIG. 2A has the lowest priority and will be downgraded first. In step  124  the type of downgrade is determined, that is, the new downgraded parameter associated with the communication characteristic of interest. This is done once again in accordance with the database illustrated in FIG.  2 A. In step  126  base station  84  sends an alert message to the mobile which may include an audio, vibrating or visual alert. The audio, vibrating or visual alert is used to inform the user that a downgrade in service is pending. This alert is passed over a forward channel such as a forward traffic channel, but may also be passed over a control channel. Now turning to the mobile station, in step  128  the mobile monitors its traffic and/or control channel for alert messages. In step  130  the mobile receives the alert message that was transmitted over the forward channel by base station  84  in step  126 . In step  132  the mobile acknowledges receipt of the alert by transmitting an acknowledgement over a reverse channel such as a reverse traffic channel or a control channel to base station  84  which receives the alert acknowledgement in step  134 . The acknowledge message from the mobile station may include a refusal to accept the downgrade. (It is also possible to include an acceptance of the downgrade; however, the absence of a refusal may be treated as an implicit acceptance.) The refusal may be selected by the user in response to the alert, for example, by pressing any key or uttering a command. Once the alert acknowledge is received by base station  84 , the base station determines whether a refusal has been received in the acknowledge message. If a refusal has been received, the database illustrated in FIG. 2A is checked to determine whether the mobile has a right of refusal. If in step  136  it is determined that a refusal was received and that the mobile has a right of refusal, the base station returns to step  122  to identify another user for downgrading. If a refusal is not received or if the right of refusal is not included in the database, the base station executes step  138  where it sends an alert with new parameters to the mobile. The new parameters indicate how the quality of service will be decreased. The parameters may indicate, for example, that one or more active communication channels will be dropped, that a different vocoder may be used, or that the amount of error encoding may be decreased. This message is sent to the mobile over a forward channel or over a control channel. Returning to the mobile, in step  140 , the mobile determines if the new parameters from base station  84  have been received. If the new parameters have not been received, step  142  is executed. In step  142 , the mobile determines if a time out has occurred. If a time out occurs (e.g., after 1 second), the mobile returns to step  128  where it monitors communication channels for new alerts or control information. If a message with new parameters is detected in step  140 , step  144  is executed. In step  144  the mobile acknowledges receipt of the new parameters by sending an acknowledgement message to base station  84  over a reverse channel or control channel. The base station receives the acknowledgement in step  146 . The mobile and the base station apply the new parameters, and thereby change the class of service in steps  148  and  150 , respectively. After changing the parameters, the mobile and base station return to normal operations. In the case of the mobile that involves monitoring the traffic and control channels while providing communications for the user. In the case of the base station, the base station continues to provide communication for the mobile and monitors the use of system resources for possible downgrades of other users or additional downgrades of users that have received initial downgrades. 
     When more system resources become available, it is also possible to use the same process to upgrade a user&#39;s service to a higher class. 
     Providing communication services to a user typically involves the utilization of more than a single network. As a result, it is useful to coordinate downgrades in service across several networks by combining databases from several networks and providing all of the networks with access to the database. For example and in reference to FIG. 5, mobile terminal  100  may use wireless network  162  for a portion of the communication path, but the remaining portion of the path passes  179  through PSTN  174  and LEC  178  before reaching destination terminal  198 . Database  160  is accessible to wireless network  162 , PSTN  174  and LEC  178 . Additionally, database  160  may include multiple databases such as database  106 . If wireless network  162  downgrades a user&#39;s class of service, it would be indicated in database  160  showing the current status of the call as downgraded. If PSTN  174  also had a shortage of resources and needed to downgrade users, PSTN  174  would access database  160  and see that the user using wireless network  162  has already been downgraded and therefore should not be downgraded again by PSTN  174 . As a result, PSTN  174  would select another user for downgrading and thereby more fairly distribute decreases in the class of service provided to the users. 
     FIG. 6 illustrates several different networks sharing database  160  in order to coordinate downgrades of service that may be provided by one or more of the networks. Wireless network (WLN)  162  communicates with database  160  via link  164 . Private voice network (PVN)  166  uses communication link  168  to access database  160 . Private data network (PDN)  170  uses communication link  172  to access database  160 . Public switch telephone network (PSTN)  174  accesses database  160  via communication link  176 . LEC  178  communicates with database  160  via link  180 . Asynchronous Transfer Mode (ATM) network  182  uses communication link  184  to access database  160 . Internet network  190  communicates with database  160  via link  194 . The link between each network and database  160  may be a direct communication link or it may include a communication path through one or more of the other networks. 
     FIG. 7 illustrates a portion of wireless network  162 . The wireless network monitors resource availability and, when necessary, accesses database  160  over link  164  to select a user for downgrading. Wireless network  162  includes mobile switching center  210  and base station  220 . Mobile switching center (MSC)  210  communicates with PSTN  174  to send and receive calls. Calls to and from PSTN  174  are handled by switch  222  which routes the calls to one of vocoders  224 ,  226  and  228 . The outputs of the vocoder are then transferred to interface unit  230  which transmits the calls over communication link  232  to interface  234  of base station  220 . The calls from interface unit  234  are passed to channel controller (CC)  236  which sends the call to one of radios  238 , 240  and  242 . The outputs of the radios are summed in summer  244  and amplified by amplifier  246  and transmitted to a mobile user over antenna  248 . Mobility Management Processor (MMP)  250  located in MSC  210  monitors resource availability for the mobile switching center and the base station. It is also possible to locate MMP  250  in a separate location that monitors several mobile switching centers and their associated base stations. MMP  250  monitors, for example, the availability of vocoders to switch  222 . Some of the vocoders may be higher rate vocoders that offer superior speech quality and other vocoders may be lower rate vocoders that do not offer a high level of speech quality. When MMP  250  detects a lack of available higher rate vocoders, it will access database  160  to select a user to be downgraded to a lower rate vocoder thereby making a higher rate vocoder available for higher priority users. It should be noted that the bank of vocoders associated with switch  222  may be located in base station  220  as an alternative to locating them in mobile switching center  210 . MMP  250  also monitors the availability of radios in base station  220  via link  232 . If the availability of radios associated with a digital channel is below a threshold and thereby makes it difficult to provide digital communication channels to high priority callers, MMP  250  accesses database  160  to select a user to be downgraded to an analog channel using an analog radio and thereby makes a digital radio available for a higher priority user. 
     FIG. 8 illustrates a portion of a communication network. The communication network receives and sends calls through ports  270  and  272 . The incoming and outgoing communications typically occur over a set of physical channels  274 ,  276 ,  278  and  280  and at least one other set of physical channels such as channels  282 , 284 , 286  and  288 . Switch  290  is used to provide connectivity between physical channels  274  through  280 , and physical channels  282  through  288 . It should be noted that each of the physical channels may contain a large number of virtual channels that are placed in time slots transmitted on each of the physical channels. This type of switch may be used in a network such as a PSTN, a data network or an ATM network. Switch controller  292  monitors the availability of channels and the number of channels being provided to a particular user. If the number of spare channels falls below a threshold, controller  292  accesses database  160  via link  294  to select a user that will be downgraded by having the number of channels provided to that user reduced. By reducing the number of channels to one or more selected users, additional channels are made available for new users or higher priority users. 
     FIG. 9 illustrates a portion of internet  190  and internet service provider (ISP)  300 . ISP  300  communicates with users  302 , 304  and  306  over LEC  308 , PSTN  310  and cable network (CN)  312 , respectively. The users typically communicate using modems. The signals from the users&#39; modems are received by switch  314  which provides connections to banks of modems  316  and  318 . The outputs from the modems are processed by interface processor  320  so that the signals are formatted according to an agreed upon protocol between ISP  300  and network  322 . Controller  324  monitors the function of switch  314  and the availability of a modem in banks  316  and  318 . If controller  324  detects that the number of high speed modems has fallen below a threshold, controller  324  will access database  160  over link  326  to select a user for downgrading. The user will be downgraded by being switched from a higher speed modem to a lower speed modem. This will make additional high speed modems available for higher priority users. 
     Interface processor  320  provides the communications from ISP  300  to internet  190  via network  322 . Network  322  communicates with other networks within the internet such as networks  325 ,  326 ,  328  and  330  via routers such as routers  332 ,  334 ,  336  and  338 . Each of the networks also monitors the availability of its resources, for example, as was discussed with regard to FIG.  8 . When one or more of the networks detect a lack of available resources, the network accesses database  160  to select a user for service downgrading. Each network may directly access database  160  over a link such as link  340 , or a network may communicate with database  160  through other networks and routers that provide access to a direct link to database  160 .