Patent Publication Number: US-9414178-B2

Title: Inter-carrier differentiation using allocation and retention priority in a wireless communication system

Description:
TECHNICAL FIELD 
     Wireless communications, and in particular to a method and system for controlling provision of services to a visiting subscriber in a wireless communication network. 
     BACKGROUND 
     An issue for service providers in a communication network is how a service provider of a visited network is to treat a customer of another service provider when the customer roams into the visited network. One possibility is for the service provider of the visited network to treat visiting subscribers the same as subscribers of the service provider of the visited network. Thus, both visiting and home subscribers could share the same quality of service and types of service provided by the provider of the visited network. This approach may be unsatisfactory since there may be constraints on the services and quality of service that can be provided to both visiting and home subscribers. On the other hand, a service provider of a visited network may desire to offer different qualities of service to visiting subscribers and home subscribers, pursuant to, for example, a service level agreement (SLA) between the service provider of the visited network and a service provider of the home network of the visiting subscribers. However, current Long Term Evolution (LTE) standards do not specify a method to provide inter-carrier differentiation to allocate or preempt services provided to visiting and home subscribers. 
     SUMMARY 
     Methods and systems for allocating services to a first subscriber of a first home service provider when the first subscriber is visiting a network associated with a visited service provider are provided. A node of the visited network receives a request from the visiting first subscriber to receive a first service from the visited network. In response to the request, the visited network determines whether there are sufficient available resources of a first set of resources to provide the requested first service. When the available resources are insufficient to provide the requested service, then at least one pre-existing service supported by the first set of resources is preempted so that sufficient resources from the first set of resources are made available to provide the requested service, and the requested service is provided to the visiting first subscriber. 
     According to another aspect, a wireless communication system having a memory and a processor is provided. The memory stores rules for allocating resources to subscribers and preempting services to subscribers within the wireless communication system. The processor is configured to allocate a first service to a first one of a first set of subscribers based on available resources and according to the stored rules. The processor preempts at least one pre-existing service according to the stored rules for at least one of a second set of subscribers so that enough resources are made available to provide the first service to the first one of the first set of subscribers. 
     According to yet another aspect, a method of differentiating between subscribers of different vendors in a wireless communication network of a first vendor that is visited by a subscriber of a second vendor is provided. A node of the first vendor determines whether sufficient resources of a first set of resources are available to provide a first service to a visiting subscriber of the second vendor. When insufficient resources of the first set of resources are available, a pre-existing service supported by a second set of resources is preempted so that enough resources are made available to support the first service, and the first service is then provided to the visiting subscriber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: 
         FIG. 1  is a block diagram of an exemplary communication system constructed in accordance with principles of the present invention; 
         FIG. 2  is a block diagram of an exemplary network node constructed in accordance with principles of the present invention; 
         FIG. 3  is a flowchart of an exemplary process for allocation and preemption of services in accordance with principles of the present invention; and 
         FIG. 4  is a flowchart of an exemplary process for allocation and preemption of services in accordance with principles of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Before describing in detail exemplary embodiments that are in accordance with the present invention, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to controlling the provision of services to a visiting subscriber by a visited network. Accordingly, the system and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. 
     As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. 
     In embodiments described herein, a service level agreement (SLA) between a home network service provider of a visiting subscriber and a visited network may be executed and in effect. In this case, the visited network service provider may decide, based on one or more terms of the SLA, whether to admit and allocate resources to a visiting subscriber. The decision may be based on an Allocation and Retention Priority (ARP) assigned to a vendor and services identified as preemption-vulnerable. 
     Referring now to the drawing figures, in which like reference designators denote like elements, there is shown in  FIG. 1  an exemplary communication network  100  having first, second and third operators  102   a ,  102   b  and  102   c . These operators may be referred to herein collectively as operators or service providers or vendors  102 . Each service provider  102  operates a radio access network (RAN)  104   a ,  104   b  and  104   c , referred to herein collectively as radio access networks  104 . Although one RAN  104  for each service provider  102  is shown, a service provider may operate more than one RAN  104 . A RAN  104  may be, for example, a Long Term Evolution (LTE) RAN. 
     In  FIG. 1 , RAN  104   c  is visited by one or more visiting subscribers  106 . For example, visiting subscribers  106   a  and  106   b  are registered with home RAN  104   a , and visiting subscriber  106   c  is registered with RAN  104   b . More or fewer visiting subscribers may be visiting RAN  104   c  at any particular time. As used herein, it is understood that the term “visiting subscriber” such as visiting subscriber  106  refers to the user equipment (UE) of a visiting customer. As used herein, the home network  104   a  or  104   b  refers to the network where the visiting subscriber is registered, e.g., obtains general monthly service, and the visited network  104   c  is a network that a subscriber visits but with which the subscriber is not registered. 
     In one embodiment, a home network  104   a  or  104   b  and visited network  104   c  are wireless communication LTE networks. However, the invention is not limited to such. It is contemplated that the home network  104   a  and/or  104   b , and visited network  104   c  can be based on any suitable wireless communication network standard that can support and implement the functions described herein, for example, networks based on 3rd Generation Partnership Project (3GPP) technologies and standards. 
     Each RAN  104  may have a plurality of evolved nodes B (eNODE B) referred to herein as base stations  108 , such as base stations  108   a  and  108   b . It is understood that the invention is not limited to LTE eNODE B base stations, and that other base station technologies may be used. When a visiting subscriber  106  is near a base station  108   a  or  108   b , the visiting subscriber  106  may seek to establish a connection with the base station  108   a  or  108   b . The base stations  108  communicate with a respective mobile management entity (MME)  110 , which in turn communicates with a respective system architecture evolution (SAE) gateway (GW)  112 . In turn, the SAE GW  112  communicates with the operator  102   c  via a communication network  114 , such as the Internet. Note that the configurations of the radio access networks  104  shown in  FIG. 1  are exemplary. Different quantities of the elements of these networks may be employed than are shown, and their connectivity may be different from that shown. For example, a RAN may include more or less than two eNODE B elements, and more or less than one MME and/or SAE GW. In some embodiments, the eNODE B elements may be connected only to the MME and not directly to the SAE GW. 
     The operator  102   c  may include a network node  116  having parameters  118  that determine under what conditions services are to be provided to a visiting subscriber  106 . The network node  116  may be, for example, a home subscriber server (HSS), a policy and charging rules function (PCRF) device, an authentication, authorization and accounting (AAA) device or an Internet Protocol (IP) multimedia subsystem (IMS). The parameters  118  may also be stored in each base station  108  and included in parameters  120   a  and  120   b  of base stations  108   a  and  108   b  respectively. Further, each base station  108   a  and  108   b  may have installed an approval function  122   a  and  122   b , respectively. 
     When a visiting subscriber  106  comes in the neighborhood, i.e., within range, of a base station  108  of the radio access network  104   c  and communication between the base station  108  and the visiting subscriber  106  is established, the base station  108  may, via the MME  110 , the SAE GW  112  and the communication network  114 , notify the service provider  102   c  of the presence of the visiting subscriber  106  in the visited network  104   c . The parameters  116  and/or the parameters  120   a  and  120   b , may specify preemption vulnerable services. A preemption vulnerable service is a service provided to a first subscriber that may be preempted in favor of a service to be provided to second subscriber. 
     In one scenario, a visiting subscriber  106  enters the visited network  104   c  and sends a request to the base station  108   a  of the RAN  104   c  for one or more services. Each base station  108   a  and  108   b , has an approval function  122   a  and  122   b , respectively, referred to collectively as approval functions  122 . Upon receipt of the request, the service approval function  122  determines, based on parameters  120   a , whether to admit the subscriber  106 , and/or approve the service or services requested by the visiting subscriber  106 . In another scenario, the visiting subscriber  106  is already admitted to the visited network  104   c  and is now requesting a new service. Upon receipt of the new request, the service approval function  122   a  determines, based parameters  120   a , whether to approve the new service requested by the visiting subscriber  106 . In yet another scenario, the visiting subscriber  106  may be powered down initially, and then awaken within the visited network  104   c . Upon awakening, the visiting subscriber  106  may request a new service. Once again, upon receipt of the request from the visiting subscriber  106 , the service approval function  122   a  determines, based on parameters  120   a , whether to approve the service requested by the visiting subscriber  106 . Thus, in the embodiment of  FIG. 1 , the service approval function  120   a  is located at the base station  108   a . In an alternative embodiment, the service approval function may be located at the centralized network node  116  of the operator  102   c.    
       FIG. 2  shows a more detailed view of an exemplary base station  108  of the service provider  102   c  of the visited network  104   c  that may be employed to implement the service control functions described herein. The base station  108  has a memory  124  and a processor  126 . The memory  124  stores rules  128  for allocation of resources and preemption of services. The rules may be based on one or more service level agreements (SLA)  130  between the vendor of the visited network and other vendors of other networks. The memory  124  may also store a list  132  of preemption-vulnerable services and a prioritized list  134  of network service providers. 
     The processor  126  includes an allocation function  136  and a preemption function  138 . The combination of the allocation function  136  and the preemption function  138  form the approval function  122  of the base station  108  as shown in  FIG. 1 . Note that other components may be included in the base station  108  such as interfaces, displays, bus structures, etc. These components are not shown in  FIG. 2  for ease of understanding the invention. 
     The rules  128  for allocation and preemption may cause the processor  126  to preempt at least one pre-existing service by identifying a preemption-vulnerable service being provided to at least one of a second set of subscribers associated with a vendor different from the vendor of a first subscriber requesting service. A rule may cause the processor  126  to preempt at least one pre-existing service by identifying a service provider associated with the second set of subscribers that has a lower priority than a service provider associated with the first subscriber. A rule may further cause the processor  126  to preempt at least one pre-existing service based at least in part on a determination that the second set of subscribers are receiving services that exceed a pre-determined allocation of resources to a service provider associated with the second set of subscribers. A rule may cause the processor  126  to preempt at least one pre-existing service based on a determination that the pre-existing service has a lower priority than a service requested by a first visiting subscriber. It will be understood that rules may apply to preempt or allocate service to additional sets, such as a third set of subscribers of a third vendor based on an SLA between the third vendor and the vendor of the visited network. 
     Table 1 below shows exemplary service level agreement (SLA) configurations to control services provided to a visiting subscriber  106  based on an SLA between the visiting subscriber&#39;s vendor (home service provider)  102   a  or  102   b , and the service provider  102   c  of the visited network  104   c . The data of Table 1 may be stored in the network node  116  of the operator  102   c  and/or may be stored in one or more of the base stations  108 . In Table 1, the term “vendor” refers to the home service provider  104   a  or  104   b  of the visiting subscriber  106 . Although Table 1 and the corresponding discussion herein is referenced to an SLA, it is understood that the parameters of Table 1 can be based solely on parameters established by the service provider  102   c  of the visited network  104   c  without regard to any actual agreement. 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                   
                   
                 Vendor&#39;s ARP 
                 Vendor&#39;s 
               
               
                   
                   
                   
                   
                 pre-emption 
                 pre-emption 
               
               
                   
                   
                   
                   
                 capability 
                 vulnerability 
               
               
                   
                   
                   
                 Vendor&#39;s 
                 (a list of 
                 (a list of 
               
               
                   
                 Vendor&#39;s 
                 Direc- 
                 ARP 
                 QCIs with 
                 QCIs with 
               
               
                 SLAI 
                 Priority 
                 tion 
                 Priority 
                 this capability) 
                 this capability) 
               
               
                   
               
             
            
               
                 1 
                 1 (highest) 
                 Uplink 
                 1 (highest) 
                 {1, 2, 3, 4, 10, 
                 {5-9, 11, 13- 
               
               
                   
                   
                   
                   
                 12} 
                 255} 
               
               
                   
                 1 (highest) 
                 Down- 
                 1 (highest) 
                 {1, 2, 3, 4, 10, 
                 {5-9, 11, 13- 
               
               
                   
                   
                 link 
                   
                 12} 
                 255} 
               
               
                 . . . 
                 . . . 
                 . . . 
               
               
                 y 
                 255 
                 Uplink 
                 15 
                 {1, 3} 
                 {2, 4-255} 
               
               
                   
                 255 
                 Down- 
                 15 
                 {1, 3} 
                 {2, 4-255} 
               
               
                   
                   
                 link 
               
               
                   
               
            
           
         
       
     
     Note that an SLA indicator (column 1 of Table 1), which is an identifier associated with an SLA, can be configured with single values or with a range of values. The SLAI provides a way to associate a service level agreement between two service providers with an identifier that can easily be communicated to all nodes that use it. The actual SLA details may be signaled from a centralized node  116  to other distributed nodes  108 . Note also that some services are bi-directional, utilizing both the uplink and the downlink. In such case, a service to be preempted may be preempted on both the uplink and the downlink, and a service to be admitted may be admitted on both the uplink and the downlink. The Quality of Service (QoS) Class Identifier (QCI) is a number that identifies a table of characteristics of one or more services. The entry of a QCI in the column entitled “Vendor&#39;s ARP pre-emption capability” indicates that the services associated with the QCIs may preempt other services. The entry of a QCI in the column entitled “Vendor&#39;s pre-emption vulnerability” indicates that the services associated with the QCIs may be preempted by other services. 
     The admission control procedures described herein may be utilized to allocate services and preempt services when enough resources do not exist to provide services to all subscribers in a radio access network including visiting subscribers. Suppose, for example, that a visiting subscriber (VS) A, whose home network is RAN A associated with vendor A, visits RAN C associated with a vendor C, so that RAN C is the visited network. Suppose further that all resources of RAN C allocated by an SLA to vendor A are exhausted and the new VS A roams into RAN C. The following method may be followed to free resources to be made available to provide service to VS A. 
     First, if the services for VS A are configured to be able to preempt other services, then RAN C can look for services that belong to vendor A that are configured as preemption-vulnerable in order to free resources for the new services to be afforded to VS A. Then, from a list of preemption-vulnerable services from vendor A, the services with the lowest allocation and retention priority (ARP) are terminated first in order to free resources to be afforded to VS A. Once sufficient resources are freed, the services requested by VS A are provided to VS A by the RAN C. 
     As another example, suppose the RAN C of vendor C is congested and VS A roams into RAN C and requests a service. The following steps may be followed to free resources for VS A. The vendor C will attempt to free preemption-vulnerable resources allocated to vendors other than vendor A that have exceeded their allocated resources. If this step does not provide enough resources to enable provision of the requested service to VS A, vendor C attempts to free resources from vendors with lower vendor priority than vendor A. The preemption-vulnerable services of the vendors with the lowest priority may be preempted to free resources. 
     As yet another example, when congestion is detected in RAN C of vendor C, one or more services may be preempted to avoid packet discards of higher priority services. First, vendors exceeding their allocated resources can have services preempted if such services are identified as preemption-vulnerable. Services with lower ARP may be preempted before services with higher ARP. If no vendors are exceeding their allocated resources, then vendor C attempts to free resources by preempting preemption-vulnerable services currently being utilized. 
     An exemplary process for allocation and preemption of services in accordance with principles of the present invention is described with reference to  FIG. 3 . A request is received in a network of a vendor C from a visiting first subscriber of a vendor A for a first service (step  140 ). A determination is made as to whether the visited network is congested (step  142 ). If the visited network is not congested, then a determination is made as to whether there are sufficient resources available to provide the first service to the visiting first subscriber (step  144 ). If there are sufficient resources available to provide the first service to the visiting first subscriber, then the first service is provided to the visiting first subscriber (step  146 ). If the network is congested or there are insufficient available resources to provide the requested service, then, if the requested service can pre-empt other services according to the SLAs, a determination is made as to whether there are preemption-vulnerable services allocated to vendor A (step  148 ). This determination may be based on terms of a service level agreement between the vendor A and the vendor C. If there are no preemption-vulnerable services allocated to vendor A, then the request for the service is denied (step  150 ). If there are preemption-vulnerable services allocated to vendor A, the preemption-vulnerable services are preempted so that there are enough free resources allocated to support the requested service (step  152 ). Then, the first service is provided to the visiting first subscriber (step  146 ). 
     An exemplary process for allocation and preemption of services in accordance with principles of the present invention is described with reference to  FIG. 4 . In contrast to  FIG. 3 , which addresses the case of preempting service only of the same vendor as the home vendor of the visiting subscriber,  FIG. 4  addresses the case where services of a third vendor B may be preempted as well. 
     A request is received by a vendor C from a subscriber of vendor A that has roamed into or awakens in the network C of vendor C (step  154 ). A determination is made whether there are sufficient resources allocated to subscribers of vendor A available to provide the requested service to the visiting subscriber (step  156 ). If there are sufficient resources allocated to vendor A available, then the requested service is provided to the visiting subscriber (step  158 ). If there are not sufficient resources allocated to vendor A available, then a determination is made whether another network B has lower priority than network A for the requested service (step  160 ). This determination may be based on terms of first SLA between provider B and provider C and a second SLA between provider A and provider C. If network B does not have a lower priority than network A, then a decision may be made, in some embodiments, to preempt a preemption-vulnerable service being provided to a second subscriber of vendor A (step  162 ). Upon preemption of the preemption-vulnerable service, the requested service is provided to the first visiting subscriber (step  158 ). 
     Returning to step  160 , if network B has a lower priority than network A, then a determination is made whether there are sufficient resources allocated to network B available and allocable to vendor A to provide the requested service to the visiting subscriber (step  164 ). If there are sufficient resources allocated to network B available, then the requested service is provided to the visiting subscriber using the available resources of vendor B (step  158 ). If there are not sufficient resources allocated to network B available, preemption-vulnerable services provided to a subscriber of vendor B are preempted (step  166 ), and the freed resources are utilized to provide the requested service to the visiting first subscriber (step  158 ). SLAs between vendor B and the visited vendor C may include a minimum amount of resources reserved to be used exclusively for subscribers of vendor B, and such resources may not be used for subscribers of other vendors, such as subscribers of vendor A. 
     Advantages of the described embodiments include providing methods to enable a network operator to meet inter-carrier agreements, including Quality of Service (QoS) agreements. A mapping of vendors to terms of a service level agreement (SLA) can be stored at a centralized node and/or at each node that uses the SLA. For instance, the SLA terms may be stored at a centralized node of the network operator and signaled to the base stations of the network as needed. Each base station may or may not be free to override the terms of the SLA. Thus, embodiments provide a method for differentiating subscribers across multiple service providers by allowing or disallowing admission of user equipment (UE) into a network based on the SLA between service providers. Further, resources may be de-allocated in order to free resources when the network is congested to allow a new UE to be admitted or simply to reduce congestion. 
     The present invention can be realized in hardware, or a combination of hardware and software. Any kind of computing system, or other apparatus adapted for carrying out the methods described herein, is suited to perform the functions described herein. A typical combination of hardware and software could be a specialized computer system, having one or more processing elements and a computer program stored on a storage medium that, when loaded and executed, controls the computer system such that it carries out the methods described herein. The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which, when loaded in a computing system is able to carry out these methods. Storage medium refers to any volatile or non-volatile storage device. 
     Computer program or application in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following a) conversion to another language, code or notation; b) reproduction in a different material form. 
     It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.