Patent Publication Number: US-2015087318-A1

Title: Dual-protocol femtocell-less communications

Description:
BACKGROUND 
     The present invention relates to the field of communication, and more particularly, to dual protocol communication. 
     The evolution of cellular networks is towards higher data capacity and hence advanced and high speed multimedia applications, especially in the indoor environment. 
     Today Global System for Mobile Communications (GSM) and 3G Wideband Code Division Multiple Access (WCDMA) network deployment in capacity mode is such that the average distance between adjacent base stations is 500 to 800 meters in dense urban environment. High Speed Packet Access (HSPA), Long Term Evolution (LTE) deployment and 4G and 5G technologies require much denser topology of base stations. This requirement is hard to fulfill because of regulation constraints, site acquisition limitations, and excessive costs. 
     A solution  70  to the indoor coverage of high capacity cellular deployment for user equipment (UE)  80  is the Home Node B (HNB), also known as femtocell  85 . Femtocell  85  is a cellular access point containing a single sector radio base station and the associated Radio Node Controller (RNC) functionality. Femtocell  85  connects to the cellular operator&#39;s network  90  via the public internet connectivity available in the indoor. This interface is called the Iuh interface, and it is terminated in Iuh aggregator component  91  in the operator&#39;s facility as shown in  FIG. 1A  which illustrates the femtocell solution of the prior art. 
     The 3rd Generation Partnership Project (3GPP), which is the standard body for Global System for Mobile Communications (GSM), WCDMA, LTE cellular Technologies and 4G/5G technologies, has set the Femto architecture to include base station as well as RNC functionalities. This architecture does not enable soft handoff capabilities, and as such Femto stations, which are co-sited and are operating on the same carrier frequency, may interfere with each other. 
     To mitigate interference between the mobile cellular network and the deployed Femto stations, the Femto stations deployment needs to be allocated frequencies other than those used by the cellular network. 
     A major business case, from the cellular operator&#39;s respective, is to be able to offload capacity, also called hand-in process, from the cellular network to the Femto network. This is a hard to implement since there is no communication channel between the cellular RNC and the Femto RNC. As long as there is cellular coverage, the phone will not search for the Femto network. Hence, no hand-in process. It has been proposed to modify the phone architecture so as to make hand-in possible. The means and ways of this architecture change are not yet known. 
     BRIEF SUMMARY 
     Embodiments of the present invention provides a system that includes (i) a communication router arranged to communicate with one or more user equipments (UEs) over a non-cellular protocol and further communicate via a communication link with a cellular communication network operating in a cellular communication protocol; and (ii) one or more UEs arranged to communicate with: one or more cellular base stations connected to the cellular communication network over the cellular communication protocol; and the communication router over the non-cellular protocol, wherein the. UEs are configured to switch between cellular and non-cellular communication protocols, based on predefined criteria. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which: 
         FIGS. 1B and 1C  are high level schematic block diagrams of communication systems according to some embodiments of the invention; 
         FIG. 2  is a high level schematic illustration of a communication system, according to some embodiments of the invention; 
         FIGS. 3A-3D  are high level schematic illustration of operation states of the system, according to some embodiments of the invention; 
         FIG. 4A  is a high level illustration of the client HNB registration process, according to some embodiments of the invention; 
         FIG. 4B  is a high level illustration of the client HNB registration process, according to some embodiments of the invention; 
         FIG. 4C  is a high level illustration of the connect state&#39;s hand-in mobility, according to some embodiments of the invention; 
         FIG. 4D  is a high level illustration of the operation of the client HNB, according to some embodiments of the invention; and 
         FIG. 5  is a high level schematic flowchart of a method, according to some embodiments of the invention. 
     
    
    
     It will be appreciated that for simplicity and clarity of illustration,, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. 
     DETAILED DESCRIPTION 
     Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining,” or the like, refer to the action and/or processes of a computer or computing system, or similar electronic computing device, that manipulates and/or transforms data represented as physical, such as electronic, quantities within the computing system&#39;s registers and/or memories into other data similarly represented as physical quantities within the computing system&#39;s memories, registers or other such information storage, transmission or display devices. 
     References in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. 
     Prior to setting forth the detailed description, it may be helpful to set forth definitions of certain terms that will be used hereinafter. 
     The term “cellular protocol” as used herein in this application refers to any communication protocol which is used in cellular communications such as 3GPP, 3GPP2 and any other protocol used in 3G/4G/5G communications. 
     The term “non-cellular protocol” as used herein in this application refers to any communication protocol which is not a cellular protocol, for example, an IEEE802.11xx protocol for WiFi communication, an internet protocol, a Bluetooth protocol etc. 
     The term “femtoless client module” as used herein in this application refers to a communication management software module that is configured to manage communication of user equipment (UE) to a cellular network via at least one cellular protocol and via at least one non-cellular protocol. 
     Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is applicable to other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
       FIGS. 1B and 1C  are high level schematic block diagrams of communication systems according to some embodiments of the invention. Systems  100  implement optional communication that avoids cellular air interface for achieving the benefit of interference reduction. 
     An alternative system  100  to the femtocell solution ( FIG. 1A ), as well as to future telephone architecture changes, is suggested so as to overcome the above mentioned problems. It is proposed to incorporate an Iuh, by way of a 3G example, client program within the Mobile Station (MS) or the User Equipment (UE), such as a wireless telephone, so that when any broadband, such as cable or Bluetooth or Wi-Fi  99 , is available, UE  110  may communicate with aggregator  91  using Iuh protocol over IP over the broadband. As an example Wi-Fi connectivity via router  130  is shown in  FIG. 1B . An application program, in UE  110 , may govern the information exchange between UE  110  and cellular core  90  that includes Iuh aggregator component  91 , over broadband connection  97 . That application program is also referred to as client HNB. 
     In cases in which it may be desired to incorporate the client HNB within broadband router  130 , another application program, or client UE, may be required in UE  110 . An example showing WiFi  99  as the broadband connectivity of choice is shown in  FIG. 1C . 
       FIG. 2  is a high level schematic illustration of a communication system  100 , according to some embodiments of the invention. 
     System  100  comprises a communication router  130  arranged to communicate with one or more user equipment (UEs)  110  over a non-cellular protocol and further communicate via a communication link  97  with a cellular communication network  90  operating in a cellular communication protocol (e.g. 3GPP/3GPP2). 
     System  100  further comprises one or more UEs  110  comprising a femtoless client module  120 , arranged to communicate with one or more cellular base stations  95  connected to cellular communication network  90  over the cellular communication protocol of communication link  98 . UEs  110  are further arranged to communicate with communication router  130  over the non-cellular protocol of communication link  99 . Femtoless client module  120  may be controlled by a controller  115  according to conditions and costs of communications. UEs  110  are configured to switch between non-cellular communication (communication links  99  and  97  via router  130 ) and cellular communication (communication link  98 ), based on predefined criteria. In particular, using the non-cellular protocols enables an implementation of system  100  that avoids cellular air interface. 
     Femtoless client module  120  may comprise a communication management software module that is configured to manage communication of user equipment (UE  110 ) to a cellular network  90  via at least one cellular protocol (any communication protocol which is used in cellular communications) and via at least one non-cellular protocol (any communication protocol which is not a cellular protocol). Femtoless client module  120  may communicate with cellular network  90  over a similar communication link to the one used by a femtocell router, e.g. Iuh/IP as illustrated in  FIGS. 1A-1C . 
     For example, communication link  99  may be wireless (e.g. WiFi, Bluetooth or other) or by wire  99 A (e.g. to an internet router such as a cable modem, e.g. ADSL). Router  130  may accordingly communicate with UE  110  wirelessly  99  or over wire  99 A, in the latter case router  130  is embodied as a wired router  130 A. Communication of router  130 ,  130 A with cellular communication network  90  may be carried out over corresponding communication links  97 ,  97 A, which may be wired or wireless. 
     In some embodiments, femtoless client module  120  may be implemented outside UE  110 , e.g. in a thin client HNB  130  ( FIG. 1C ) or in a thin Femtocell router that communicates with UE  110  over a non-cellular protocol (e.g. an IEEE802.11xx protocol) and serves merely as an interface between UE  110  and network  90 . 
     UE&#39;s  110  may be further arranged to detect communication loss in one of the non-cellular and the cellular protocols and switch communication to the other of the non-cellular and the cellular protocols, as described below. 
     System  100  may be arranged to provide communication to UE&#39;s  110  via an available communication route using at least one of the non-cellular and the cellular protocols, as described below. 
       FIGS. 3A-3D  are high level schematic illustration of operation states of system  100 , according to some embodiments of the invention.  FIGS. 3A-3D  illustrate the operation states using a WiFi access point  130  as a non-limiting example for router  130 . Similar implementation may be carried out using other embodiments of router  130 . 
       FIG. 3A  illustrates an idle state  140 A in which, when UE  110  is camped on base station  95  (e.g. a 3G/LTE macro) and is idle, i.e. not in connect mode, and WiFi access point  130  is detected, controller  115  such as the client HNB establishes client HNB registration followed by UE registration, and camps on WiFi  130 . Femtoless client module  120  interfaces between non-cellular and cellular protocols. 
       FIG. 3B  illustrates a client idle state  140 B in which, when UE  110  is camped on WiFi access point  130  and is idle, i.e. not in connect mode, and the WiFi signal is lost, controller  115  e.g. the client HNB may reestablish UE registration on base station  95  e.g. the 3G macro, and camps thereon (e.g. on the 3G/LTE macro). 
       FIG. 3C  illustrates a connect state  140 C in which, when UE  110  is camped on base station  95  e.g. a 3G/LTE macro and is connected, i.e. data transfer is in progress, and WiFi access point  130  (as an example for router  130 ) is detected, controller  115  e.g. the client HNB may establish client HNB registration followed by UE registration, and follows the connected mode hand in mobility procedure described below, over WiFi channel  99 . Femtoless client module  120  communicates with cellular network  90  over non-cellular protocols. 
       FIG. 3D  illustrates a client HNB connect state  140 D in which, when UE  110  is camped on WiFi access point  130  and is connected, i.e. data transfer is in progress, and the WiFi signal is lost, controller  115  e.g. the client HNB may reestablish UE registration over 3G/4G communication link  98  e.g. the 3G/LTE macro network, and follows the cell relocation procedure as specified e.g. by the 3GPP standard. Femtoless client module  120  may use non-cellular protocols to communicate cellular communication from UE  110 . The client performs all of the functions required by the 3GPP standard such as: Client HNB registration, UE registration, connected mode hand-in mobility, connected mode hand-out mobility, Q&amp;M for client HNB, as well as data and circuit switch data transfer. 
     Steps of the above described states  140 A- 140 D are illustrates in the following diagrams. 
       FIG. 4A  is a high level illustration of the client HNB registration process, according to some embodiments of the invention. Controller  115  may perform Client HNB initialization (stage  151 ) to obtain HNB configuration from the client HNB Management System (HMS). Similarly, HNB Gateway (HNB-GW  112 ) discovery is performed to obtain the initial serving HNB-GW information. 
     The process comprises the following stages: (i) The client HNB establishes a secure tunnel to the Secure Gateway (SeGW  111 ) of the serving HNB-GW (stage  152 ). (ii) The client HNB sets up a reliable transport session, such as, an SCTP transport session to a well-defined port on the serving HNB-GW (stage  153 ). (iii) The client HNB then attempts to register with the serving HNB-GW using an HNB REGISTER REQUEST message (stage  154 ). 
     The message may contain Client HNB Location Information, Client HNB Identity (the client HNB has a globally unique and permanent identity), and Client HNB Operating Parameters (Such as the selected Location Area Code (LAC), Routing Area Identifier Code (RAC), Service Area Code (SAC), Public Land Mobile Network (PLMN) Id, Cell Id, etc.). 
     The client HNB provides location information via use of one or more of the following mechanisms: Detected macro-cell coverage information, e.g. GSM edge Radio Access Network (GERAN) and/or UMTS Terrestrial Radio Access Network (UTRAN) cell information; Geographical co-ordinates, e.g. via use of Global Positioning System (GPS), etc.; and Internet connectivity information (e.g. IP address), provided, the resulting location information is at least as accurate as location determination based on macro-cell coverage information, whether or not there is macro cell-coverage available at the location of the client HNB (e.g. as determined by point i above). 
     HNB-GW  112  may use the information from the HNB REGISTER REQUEST message to perform access control of the client HNB (e.g. whether a particular client HNB is allowed to operate in a given location, etc). If HNB-GW  112  accepts the registration attempt it shall respond with a HNB REGISTER ACCEPT message. If HNB-GW  112  has capability to de-multiplex, HNB-GW  112  may include a Multiplexer (MUX) port in the HNB REGISTER ACCEPT message. Alternatively, HNB-GW  112  may reject the registration request (e.g. due to network congestion, blacklisted client HNB, unauthorized client HNB location, etc). In this case, HNB-GW  112  shall respond with an HNB REGISTER REJECT indicating the reject cause. 
       FIG. 4B  is a high level illustration of the client HNB registration process, according to some embodiments of the invention. Controller  115  may perform the client HNB registration process according to the following stages. 
     Upon camping on Wi-Fi access point  130 , UE  110  initiates an initial Non Access Stratum (NAS) procedure (e.g. Location Update (LU) Procedure) by emulating a Radio Resource Control (RRC) connection with client HNB  113  (stage  161 ). UE identity and UE capabilities, e.g. “Access stratum release indicator” or “UE feature capability indicator”, are reported to client HNB  113  as part of the RRC Connection establishment procedure. 
     UE  110  then forwards to client HNB  113  an RRC Initial Direct Transfer message carrying the initial NAS message (e.g. Location Updating Request message) with some form of identity (e.g. IMSI or TMSI etc.) (stage  162 ). 
     Client HNB  113  checks the UE capabilities provided in stage  161  (stage  163 ), and if these indicate, for example, that Closed Subscriber Group (C 5 G) is supported and if the identity of UE  110  (provided during RRC Connection Establishment) is unknown, i.e. no Context id exist for UE  110 , client HNB  113  initiates UE registration towards HNB-GW  112  (stages  164 - 166 ). If client HNB  113  has a context id for UE  110 , UE registration procedure is not performed. No Identification procedure is triggered, independent of the identity reported by UE  110  during the RRC Connection Establishment. 
     Client HNB  113  attempts to register UE  110  on the HNB GW by transmitting the UE REGISTER REQUEST (stage  164 ). The message may contain: UE Identity: a unique identifier for UE  110  and provided in stage  161 ; UE capabilities: derived from that provided in stage  161 ; Registration Cause: the indication about a UE registration for an emergency call. NOTE: The UE IMSI/TMSI provided in the UE REGISTER message is unauthenticated. 
     HNB-GW  112  checks UE capabilities and if these indicate that CSG is supported and if client HNB  113  supports CSG, HNB-GW  112  shall accept the UE registration and allocate a context-id for UE  110  (stage  165 ). 
     HNB-GW  112  responds with a UE REGISTER ACCEPT message back to client HNB  113  including a context-id allocated to UE  110  (stage  166 ). 
     Client HNB  113  then sends a RUA CONNECT message containing the RANAP Initial UE message (stage  167 ). The RANAP Initial UE message may contain the Cell Access Mode. 
     The reception of the RUA CONNECT message at HNB-GW  112  triggers the setup of an SCCP connection by HNB-GW  112  towards Core Network  90  (CN) (stage  168 ). HNB-GW  112  then forwards the Initial UE Message including the CSG id of client HNB  113 . 
     CN  90  responds with an SCCP Connection Confirm message (stage  169 ). 
     CN  90  may optionally perform Mobility Management procedures, e.g. Authentication procedure (stage  170 ). 
     CN  90  performs access control of UE  110  (stage  171 ). 
     After being granted access UE  110  then continues with the NAS procedure (e.g. Location Updating procedure) towards CN  90 , via client HNB  113  and HNB-GW  112  (stage  172 ). During such procedures CN  90  may send to client HNB  113  the UE membership status for the accessed cell in the COMMON ID message. 
       FIG. 4C  is a high level illustration of connect state  140 C&#39;s hand-in mobility, according to some embodiments of the invention. Connect state  140 C&#39;s hand-in mobility may be handled according to the following stages. 
     UE  110  may be triggered to send an RRC Measurement Report by the rules set by the UTRAN (stage  181 ). The Measurement Report includes the Cell Identity, CSG id (if requested) of target client HNB  113 . 
     Source Radio Access network (RAN) node  114  makes a decision to relocate the UE session (stage  182 ). 
     Source RAN  114  triggers relocation of the UE session by sending the RANAP RELOCATION REQUIRED message to the Core Network (stage  183 ). The target RNC Id, CSG id. Target Cell Id and—for relocation to a hybrid cell -Cell Access Mode information along with relocation information are included by the source RAN in the RANAP RELOCATION REQUIRED message. 
     If the target cell, for example, is a CSG client HNB, the Core Network verifies that UE  110  is indeed a member of the CSG associated with the target cell, as reported to the Core Network [x1] (stage  184 ). Otherwise (if the target is a Hybrid Cell), the Core Network fills the CSG Membership Status IE in stage  185  to reflect UE  110 &#39;s membership to the CSG. 
     HNB-GW  112  receives a RANAP RELOCATION REQUEST message from the Core Network, including the CSG id (stage  185 ). Target Cell Id and—for relocation to a hybrid cell—CSG Membership Status. 
     The stages for HNB-GW Triggered UE Registration are executed between HNB-GW  112  and client HNB  113  (stage  186 ). HNB-GW  112 /HNB  113  validates the CSG id received in the RANAP RELOCATION REQUEST message. 
     The remainder of the relocation procedure continues normally as is defined by the 3GPP standard (stage  187 ). 
     Stages  182  to  187 , as appropriate, are repeated for the second CN domain when present with the following exceptions. The relocation of the 2nd domain shall not trigger an additional registration. The 2nd RANAP Relocation Request shall be carried as RUA Direct Transfer. There is only one Context Id assigned to UE  110  regardless of the number of domains relocated from source RAN  114 . 
       FIG. 4D  is a high level illustration of the operation of client HNB  113 , according to some embodiments of the invention. A secure tunnel is established from client HNB  113  to security gateway  111  (stage  191 ). Location verification is then performed by the HMS based on information sent by client HNB  113  (stage  192 ) (e.g. macro neighbor cell scans, global navigational satellite system type of information etc.). HMS (client HNB Management System  116 , embodied e.g. in controller  115 ) determines the serving elements and provides HNB GW  112 , HMS  116  and Security Gateway  111  to client HNB  113 . HMS  116  also provisions configuration parameters to client HNB  113  only after successful location verification in HMS  116 . For completeness reliable transport setup may then be performed (stage  193 ) and HNB registration procedure may commence (stage  194 ). Security gateway  111  and HMS  116  are shown to highlight the general architecture. In the event information required for verifying location are not available (for example, no macro neighbor cells, no GNSS, no DSL line ID etc. available), HNB GW discovery may be based on specific operator and/or regulatory policies. 
       FIG. 5  is a high level schematic flowchart of a method  200 , according to some embodiments of the invention. 
     Method  200  comprises the following stages, which were explained in further detail above: arranging a communication router to communicate with one or more user equipment (UEs) over a non-cellular protocol (stage  210 ) and further communicate via a wired communication link with a cellular communication network operating in a cellular communication protocol (stage  220 ); communicating, via the one or more UEs comprising a femtoless client module, with one or more cellular base stations connected to the cellular communication network over the cellular communication protocol (stage  230 ); and the communication router over the non-cellular protocol (stage  240 ); and configuring the UEs to switch between non-cellular and cellular communication, based on predefined criteria (stage  250 ). 
     Method  200  may further comprise detecting communication loss in one of the non-cellular and the cellular protocols and switching communication to the other of the non-cellular and the cellular protocols (stage  260 ), as well as registering the UE&#39;s to available communication routes (stage  270 ) and operating the UE&#39;s via the available communication routes (stage  275 ). Method  200  may further comprise implementing the femtoless client module in the communication router (stage  280 ). 
     In embodiments, some or all stages of method  200  may be implemented as a computer program product in either UEs  110  or router  130 , or distributed among UEs  110  and router  130 . 
     For example, embodiments comprise a computer program product comprising a computer readable storage medium having computer readable program embodied therewith, the computer readable program comprising: (i) computer readable program configured to communicate with one or more user equipment (UEs) over a non-cellular protocol and further communicate via a wired communication link with a cellular communication network operating in a cellular communication protocol; (ii) computer readable program configured to switch between non-cellular and cellular communication, based on predefined criteria; and (iii) computer readable program configured to communicate, via the one or more UEs with one or more cellular base stations connected to the cellular communication network over the cellular communication protocol; and with the communication router over the non-cellular protocol. The computer program product enables UE communication without cellular air interface. 
     Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment. 
     Embodiments of the invention may include features from different embodiments disclosed above, and embodiments may incorporate elements from other embodiments disclosed above. The disclosure of elements of the invention in the context of a specific embodiment is not to be taken as limiting their used in the specific embodiment alone. 
     Furthermore, it is to be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in embodiments other than the ones outlined in the description above. 
     The invention is not limited to those diagrams or to the corresponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described. 
     Different embodiments are disclosed herein. Features of certain embodiments may be combined with features of other embodiments; thus certain embodiments may be combinations of features of multiple embodiments. 
     Embodiments of the invention may include an article such as a computer or processor readable non-transitory storage medium, such as for example a memory, a disk drive, or a USB flash memory device encoding, including or storing instructions, e.g., computer-executable instructions, which when executed by a processor or controller, cause the processor or controller to carry out methods disclosed herein. 
     The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be appreciated by persons skilled in the art that many modifications, variations, substitutions, changes, and equivalents are possible in light of the above teaching. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.