Abstract:
An integrated access system for All-IP converged network is provided. According to an aspect, by integrating the common factors of existing complex wireless networks to load-reduce and simplify the wireless networks and convert them using Internet access technology to thereby simplify a network architecture, integratively operating radio accesses, ensuring end-to-end quality, and providing service adaptiveness, easiness in operation, CAPEX/OPEX, and excellent service adaptiveness can be achieved.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit under 35 U.S.C. §119(a) of Korean Patent Applications No. 10-2011-0020601, filed on Mar. 8, 2011, and No. 10-2012-0023468, filed on Mar. 7, 2012, the entire disclosures of which are incorporated herein by reference for all purposes. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    The following description relates to an All-IP converged access system capable of establishing a variety of IP networks based on different standards using single IP technology, and a control method thereof. 
         [0004]    2. Description of the Related Art 
         [0005]    Mobile-WiMAX and Evolved Packet System (EPS) including 3 rd  Generation Partnership Project (3GPP) Long Term Evolution (LTE) that is currently discussed as representative 4G technology are exposing limitation due to their problems as follows. The Mobile-WiMAX and EPS use individual independent traffic control methods (3GPP-GTP/WiMAX-GRE) for each standard in order to separate/manage and charge subscriber traffic, which causes control complexity and has been a roadblock to control unification with IP networks. The 3GPP is planning independent development of wired and wireless technologies through LTE and Evolved Packet Core (EPC) for network integration. However, since the EPC itself has been taking over the tunneling control structure of a General Packet Radio Service (GPRS) of 3G, the EPC could not solve the 3G&#39;s problems. Furthermore, since no architecture for providing mobility between heterogeneous networks (for example, between 3GPP and non-3GPP) has been yet decided, no solution for providing seamless IP mobility has been proposed although applications of MIP, PMIP, etc. are trying to provide mobility. 
         [0006]    Meanwhile, the 3GPP/Mobile-WiMAX (WiBro) network uses a different resource control system from IP networks, which becomes a factor of increasing network overhead for broadcast/multicast. Also, the 3GPP continues to add nodes/functions, such as MBMS, BM-SC, etc., and the Mobile-WiMAX (WiBro) continues to add nodes/functions, such as MBS proxy, MCBCS, etc., resulting in a further increase of network complexity. 
         [0007]    In view of QoS and service control, in the case of Mobile-WiMAX (WiBro), a policy distribution function for matching an IMS QoS system in order to accept the IMS architecture of 3GPP is defined and added as a separate node, which also leads to a continuous increase of network complexity. 
       SUMMARY 
       [0008]    The following description relates to a low-power, large-capacity integrated access system that can establish a variety of wireless subscriber networks based on different standards, such as a 3GPP Evolved Packet System (EPS), Wibro/Wibro Evolution, etc., using single IP technology, that can introduce a single IP-based control system that can be applied from a subscriber network to a backbone network to thereby optimize an IP network, and that can establish an access media independent packet-based network without having to use a multi-network architecture dependent on a mobile communication standard through termination of existing and future mobile communication specifications. 
         [0009]    In one general aspect, there is provided an integrated access apparatus for All-IP converged network, comprising a flow-based LTE base station having a function of separating traffic for each subscriber/service in unit of an IP flow and managing/controlling the separated traffic, and a flow-based M-WiMAX base station having the function of separating traffic for each subscriber/service in unit of an IP flow and managing/controlling the separated traffic. 
         [0010]    The integrated access apparatus further includes a Unified Control Entity (UCE) configured to generate a path request message for a terminal using a source IP address of the terminal, and to provide IP packet header information (5-tuple) to the base station, wherein the IP packet header information is used for routing of the terminal and included in a response message to the path request message. 
         [0011]    The integrated access apparatus further includes a packet border gateway (PBGW) configured to receive a path request message from the mobility management entity, to acquire IP packet header information (5-tuple) for routing of the terminal based on a source IP address of the terminal, and to provide the IP packet header information (5-tuple) to the mobility management entity. 
         [0012]    Therefore, by integrating the common factors of existing complex wireless networks to load-reduce and simplify the wireless networks and convert them using Internet access technology to thereby simplify a network architecture, integratively operating radio accesses, ensuring end-to-end quality, and providing service adaptiveness, easiness in operation, CAPEX/OPEX, and excellent service adaptiveness can be achieved. 
         [0013]    Also, by improving the functions of network equipment to optimize the network equipment without having to change the functions of terminals, it is possible to significantly improve a network architecture while providing an All-IP converged service. 
         [0014]    Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a conceptual view illustrating a 3GPP Evolved Packet System (EPS) network and a M-WiMAX network. 
           [0016]      FIG. 2  is a conceptual view illustrating an example of a network. 
       
    
    
       [0017]    Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated for clarity, illustration, and convenience. 
       DETAILED DESCRIPTION 
       [0018]    The following description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. Accordingly, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be suggested to those of ordinary skill in the art. Also, descriptions of well-known functions and constructions may be omitted for increased clarity and conciseness. 
         [0019]      FIG. 1  is a conceptual view illustrating a 3GPP Evolved Packet System (EPS) network  110  and a M-WiMAX network  120 . 
         [0020]    The EPS network  110  may be defined by Long Term Evolution (LTE) and an Evolved Packet Core (EPC), wherein the LTE defines a radio interface between terminals  11  and a base station (eNodeB)  112  and the EPC is defined by a Mobility Management Entity (MME)  115 , a Serving Gateway (SGW)  113 , and a PDN Gateway (PGW) 114 (3GPP TS36.300). 
         [0021]    The M-WiMAX network  120  is composed of a terminal  121 , a Base Station (BS)  122 , and an Access Service Network Gateway (ASN-GW)  123  (WiMAX Forum Network Architecture, Stage2). 
         [0022]    The EPS network  110  interworks with a general Internet  140  through an Internet Exchange Point (IX)  130 , and the M-WiMAX  120  interworks with the general Internet  140 , the EPS network  110 , etc. through the IX  130  via an IP network  150 . 
         [0023]    The EPS network  110  uses GPRS Tunneling Protocol (GTP) tunnels  117  and  118  for traffic separation for each subscriber/service, etc., and the W-WiMAX network  120  also uses a Generic Routing Encapsulation (GRE) tunnel  124  for the similar purpose, which increases the complexity of traffic control and has been a roadblock to the evolution into an All-IP converged network. 
         [0024]      FIG. 2  shows examples of a converged network and an integrated access apparatus for the converged network. 
         [0025]    Referring to  FIG. 2 , the integrated access apparatus includes a first base station  202 , a second base station  204 , a United Control Entity (UCE)  206 , and a packet border gateway (PBGW)  205 . 
         [0026]    In  FIG. 2 , the first and second base stations  202  and  204  may communicate with a LTE terminal  201  and a M-WiMAX terminal  203 , respectively. At this time, it is assumed that the LTE and M-WiMAX terminals  201  and  203  are not changed. 
         [0027]    Also, the first and second base stations  202  and  204  may additionally have a function of managing/controlling traffic for each subscriber/service in unit of IP flow. For example, the first base station  202  may be a LTE base station having a function of managing/controlling traffic for each subscriber/service in unit of IP flow. In this specification, the LTE base station  202  may be simply referred to as a flow based eNodeB (feNB). As another example, the second base station  204  may be a M-WiMAX base station having a function of managing/controlling traffic for each subscriber/service in unit of IP flow, and in this specification, the M-WiMAX base station  204  may be simply referred to as a flow based BS (fBS). 
         [0028]    The UCE  206  may generate a path request message for a terminal using the source IP address of the terminal, and provide IP packet header information (5-tuple) to the first and second base stations  202  and  204 , wherein the IP packet header information (5-tuple) is used for routing of the terminal and will be included in a response message to the path request message. For example, the UCE  206  may set or manage at least one of a data path, integrated mobility, and radio resources between heterogeneous subscriber networks, based on the IP packet header information (5-tuple). In other words, the UCE  206  may be in charge of data routing of the M-WiMAX ASN GW, integrated mobility management between heterogeneous accesses, and integrated radio resource management for LTE/M-WiMAX, as well as the functions of Mobility Management Entity (MME) defined in 3GPP TS36.300. 
         [0029]    If the UCE  206  transfers the IP packet header information to the first and second base stations  202  and  204 , the first and second base stations  202  and  204  may secure a data path based on the IP packet header information. For example, the first base station  202  maps a Radio Bearer ID (RBID) to tuple information of an IP packet, based on the IP packet header information (5-tuple), to thereby secure a data path. As another example, the second base station  204  maps a Connection ID (CID) to tuple information of an IP packet, based on the IP packet header information (5-tuple), to thereby secure a data path. 
         [0030]    The PBGW  205  accepts both the first and second base stations  202  and  205 , and controls data traffic between the PBGW  205  and the first base station  202  or the second base station  204  based on the IP packet (flow), not based on GTP or GRE. Also, the data traffic that is controlled based on the IP packet (flow) is transferred to the Internet  210  via the PBGW  205 . 
         [0031]    Also, the PBGW  205  interworks with an IP Multimedia Subsystem (IMS)  208  and a Policy and Charging Rule Function (PCRF)  209  for service call control, service QoS control, etc. 
         [0032]    Hereinafter, in the case where the first base station  202  is feNodeB and the second base station  204  is fBS, data layers, signal layers, integrated resource management, IP mobility control, service recognition automatic handover, etc., which are newly defined, will be described. 
         [0033]    &lt;Data Layers&gt; 
         [0034]    In traffic control between the PBGW  205  and the feNodeB  202  or fBS  204 , for IP packet-based control, not for GTP- or GRE-based control, the feNodeB  202 , fBS  204 , and PBGW  205  have a Micro-Flow traffic control function of managing/controlling traffic for each subscriber/service. The Micro-Flow traffic control function can separate/manage traffic for each subscriber/service with respect to signals (data) received through the Packet Data Convergence Protocol (PDCP) of the feNodeB  202  and the Convergence Sublayer (CS) of the fBS  204 . 
         [0035]    Thereby, a method of mapping a RBID of an existing eNodeB to a GTP Tunnel Endpoint ID (TEID) between the eNodeB and a SGW to secure a data path is changed to a method of mapping the RBID to 5-tuple information of an IP packet to secure a data path, and also a method of mapping a CID of a CS layer in an existing BS to a GRE key value between the BS and ASNGW to secure a data path is changed to a method of mapping the CID to 5-tuple information of an IP packet to secure a data path. An IP flow recognized by the feNodeB  202  and fBS  204  is transferred to the PBGW  205  through a layer-2 transmission function such as the Ethernet, and the PBGW  205  performs an IP transfer function, such as QoS application, routing, etc., of the IP flow. Also, the PBGW  205  performs an additional function of providing a security tunnel and IP mobility. Meanwhile, the feNodeB  202  and fBS  204  process charging information, measurement information, etc. of user traffic, based on micro-flow. 
         [0036]    &lt;Signal Layers&gt; 
         [0037]    In the EPC signal layer, there are signal schemes between a terminal and an eNB, between a MME and a terminal, between a MME and an eNB, and between a MME and a SGW (3GPP TS24.301, TS39.413, TS29.272, TS23.401). Also, In the M-WiMAX signal layer, there are direct signal schemes between a terminal and a BS and between a BS and an ASNGW. Since the current example considers no case where radio periods and terminals are changed, the signal schemes between the terminal and eNB and between the BS and terminal accept existing signal schemes as they are, and signals between the MME and terminal are based on the signal scheme between the UCE and terminal. The other signal schemes are unified to the signal schemes between the UCE and PBGW and between the UCE and base station (feNB or fBS). 
         [0038]    &lt;Integrated Resource Management&gt; 
         [0039]    Heterogeneous radio resources of LTE and M-WiMAX networks are integratively managed in order to maximize the use efficiency of radio resources. That is, the used bandwidth for each cell, the number of used radio channels for each cell, the number of subscribers for each cell, the number of subscriber traffic sessions for each cell, etc. are collected from the LTE and M-WiMAX networks, and then the collected information is integratively managed. The integrated management of radio resources is aimed at automatically handing over subscribers to a cell (a homogeneous or heterogeneous cell) having many available radio resources according to the use rate of radio resources for each cell, and this function will be described later. 
         [0040]    &lt;IP Mobility Control&gt; 
         [0041]    For IP mobility control, an IP address system in which an ID for identifying a terminal is separated from a locator for data transmission is introduced. The terminal ID is used to identify and authenticate a subscriber terminal, and the locator is used to register/manage the location information of the subscriber terminal and transmit subscriber traffic. The address of the PBGW  205  is generally used as the locator, and in a special case where high security is required, a specific ID may be separately allocated to the terminal. 
         [0042]    In the case where the address of the PBGW  205  is used as the locator, a basic IP-in-IP type of security tunnel is established between PBGWs, and in the case of a service where high security is required, an IP-in-IP type of security tunnel is established between terminals based on locators allocated to the terminals. If a locator is changed due to a terminal accessing a network or connecting to another PBGW, etc., a data path is established and thereafter the PBGW registers the location information of the terminal in the UCE  206  based on the locator. 
         [0043]    When a certain terminal requests another terminal to send a call such as data transmission, the PBGW  205  recognizes the location of the other terminal by inquiring the UCE  206  about the locator of the other terminal and receiving a response from the UCE  206 , and then establishes a data path (a security tunnel). This operation allows direct communication between terminals for a non-IMS service. If an IP address is changed upon movement of a terminal, the UCE  206  detects the movement of a L2 layer and requests a target PBGW to establish a data path. After the target PBGW establishes a data path, the target PBGW registers the location information of the moved terminal in the UCE  206 , and then the data path of the source PBGW is released. For this function, the PBGW  205  may have a function of registering the location information of a terminal in the UCE  206  or inquiring the UCE  206  about the location information of a terminal, and a function of mapping a terminal ID to routing/switching information about downward traffic to the terminal and managing the mapped information. In addition, the PBGW  205  may have an IP-in-IP En-capsulation/De-capsulation function for data transmission. 
         [0044]    &lt;Service Recognition Automatic Hand-Over&gt; 
         [0045]    When heterogeneous cells geomatically overlap each other, when a cell which a subscriber currently accesses has too many users, or when resources for receiving a service requested by a user are insufficient, the QoS of the corresponding user service may be influenced. In this case, if a heterogeneous cell adjacent (geographically overlapping with) to the corresponding cell has idle resources, the user terminal is connected to the adjacent cell, thereby providing a high quality service. For this operation, the UCE  206  and/or PBGW  205  recognizes the service characteristics for user traffic and determines the states of available resources through an integrated resource management function to thereby reconnect the terminal to the heterogeneous cell. 
         [0046]    The present invention can be implemented as computer readable codes in a computer readable record medium. The computer readable record medium includes all types of record media in which computer readable data are stored. Examples of the computer readable record medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage. Further, the record medium may be implemented in the form of a carrier wave such as Internet transmission. In addition, the computer readable record medium may be distributed to computer systems over a network, in which computer readable codes may be stored and executed in a distributed manner. 
         [0047]    A number of examples have been described above. Nevertheless, it will be understood that various modifications may be made. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Accordingly, other implementations are within the scope of the following claims.