Patent Publication Number: US-2022225073-A1

Title: Systems and methods for inter-network roaming using a private cellular network

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 63/135,311, filed on Jan. 8, 2021 and titled “SYSTEMS AND METHODS FOR INTER-NETWORK ROAMING USING A PRIVATE CELLULAR NETWORK,” the entire content of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     Field of the Disclosure 
     The present disclosure relates to operation of a private cellular network and more specifically to intra-network roaming at various deployment locations associated with a private cellular network. 
     Description of the Related Art 
     Various generations of wireless technologies and supporting networks have been designed, standardized, implemented and used globally to service millions/billions of end users. These wireless networks have evolved from analog to digital radio access systems, from circuit switching to packet core, from proprietary mobility and administrative protocols to standardized protocols, and from single provider to multi provider networks. 
     Wireless connectivity through cellular networks provides several advantages over wireless connectivity through Wi-Fi, such as faster speed, security and longer coverage range to name a few. As wireless technologies evolve and connectivity capabilities of mobile devices and Internet of Things (IoT) devices increase, many established and large cellular wireless service providers (mobile network operators) are unable to meet the increased demand. Use of private cellular networks in areas and locations where providing wireless services are impossible or economically not feasible for the larger cellular wireless service providers, can address the gap to meet the increased demand. 
     SUMMARY 
     One or more example embodiments of inventive concepts are directed to private cellular networks that provide cellular connectivity at one or more geographical locations. One or more organizations may be associated with and utilize wireless network services provided through the private cellular network. Individual devices associated with one or more of such organizations may be able to roam on and utilize cellular network connectivity available on-site at any of the one or more geographical locations and be routed to their home private cellular network Evolved Packet Core (EPC). 
     In one aspect, a private cellular network includes a common evolved packet core component; and a router configured to receive network traffic from a plurality of endpoints communicatively coupled to the router; identify each endpoint of the plurality of endpoints as (1) an endpoint registered with the private cellular network and for which the router and an associated edge evolved packet core deployed at a location, serve as a home network, or (2) an endpoint roaming on the private cellular network at the location; and route the network traffic via (1) an interface of the router to the edge evolved packet core for each endpoint registered with the private cellular network and for which the router and the edge evolved packet core server as the home network, or (2) via the common evolved packet core component to a corresponding home evolved packet core of each endpoint roaming on the private cellular network. 
     In another aspect, the router is configured to identify each end point as the endpoint registered with the private cellular network or the endpoint roaming on the private cellular network based on a corresponding Intentional Mobile Subscriber Identity (IMSI) number of each endpoint. 
     In another aspect, the common evolved packet core component routes the network traffic to an S8 interface of the corresponding home evolved packet core of a corresponding endpoint over a private virtual network. 
     In another aspect, the router is configured to route the network traffic to the common evolved packet core component via a dedicated S1 interface. 
     In another aspect, the common evolved packet core component is communicatively coupled to the router and to the corresponding home evolved packet core of each roaming endpoint. 
     In another aspect, the common evolved packet core component operates as a one-to-many hub for network traffic routing associated with one or more of the plurality of endpoints roaming on the private cellular network. 
     In another aspect, the router is further configured to identify at least one of the plurality of endpoints roaming on the private cellular network as being associated with a mobile network operator, the mobile network operator having a dedicated S1 interface on the router. 
     In another aspect, the router is configured to route corresponding network traffic of the at least one endpoint associated with the mobile network operator to a corresponding home evolved packet core of the mobile network operator via the dedicated S1 interface. 
     In another aspect, the common evolved packet core comprises a mobility management entity and a serving gateway. 
     In another aspect, the common evolved packet core is configured to locate the corresponding evolved packet core of each visiting endpoint using the mobility management entity to an Access Point Name associated with the corresponding visiting endpoint. 
     In one aspect, one or more non-transitory computer-readable media include computer-readable instructions, which when executed by one or more processors of a router of a private cellular network, cause the router to receive network traffic from a plurality of endpoints communicatively coupled to the router; identify each endpoint of the plurality of endpoints as (1) an endpoint registered with the private cellular network and for which the router and an associated edge evolved packet core deployed at a location, serve as a home network, or (2) an endpoint roaming on the private cellular network at the location; and route the network traffic via (1) an interface of the router to the edge evolved packet core for each endpoint registered with the private cellular network and for which the router and the edge evolved packet core server as the home network, or (2) via a common evolved packet core component of the private cellular network to a corresponding home evolved packet core of each endpoint roaming on the private cellular network. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate various embodiments of systems, methods, and embodiments of various other aspects of the disclosure. Any person with ordinary skills in the art will appreciate that the illustrated element boundaries (e.g. boxes, groups of boxes, or other shapes) in the figures represent one example of the boundaries. It may be that in some examples one element may be designed as multiple elements or that multiple elements may be designed as one element. In some examples, an element shown as an internal component of one element may be implemented as an external component in another, and vice versa. Furthermore, elements may not be drawn to scale. Non-limiting and non-exhaustive descriptions are described with reference to the following drawings. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating principles. 
         FIG. 1  illustrates an overview of a private cellular network ecosystem, according to an aspect of the present disclosure; 
         FIG. 2  illustrates an overview of an edge site component of a private cellular network deployed at an edge site, according to an aspect of the present disclosure; 
         FIG. 3  illustrates details of cloud and site components of ecosystem of a private cellular network, according to an aspect of the present disclosure; 
         FIG. 4  is a visual representation of an example of intra-network roaming and traffic routing via edge core router of a private cellular network, according to an aspect of the present disclosure; 
         FIG. 5  is a visual representation of another example of intra-network roaming and traffic routing via edge core router of a private cellular network, according to an aspect of the present disclosure; 
         FIG. 6  illustrates an example process for managing network traffic in a private cellular network according to an aspect of the present disclosure; and 
         FIGS. 7A and 7B  illustrate systems according to an aspect of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Specific details are provided in the following description to provide a thorough understanding of embodiments. However, it will be understood by one of ordinary skill in the art that embodiments may be practiced without these specific details. For example, systems may be shown in block diagrams so as not to obscure the embodiments in unnecessary detail. In other instances, well-known processes, structures and techniques may be shown without unnecessary detail in order to avoid obscuring embodiments. 
     Although a flow chart may describe the operations as a sequential process, many of the operations may be performed in parallel, concurrently or simultaneously. In addition, the order of the operations may be re-arranged. A process may be terminated when its operations are completed, but may also have additional steps not included in the figure. A process may correspond to a method, function, procedure, subroutine, subprogram, etc. When a process corresponds to a function, its termination may correspond to a return of the function to the calling function or the main function. 
     Example embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings in which like numerals represent like elements throughout the several figures, and in which example embodiments are shown. Example embodiments of the claims may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein. The examples set forth herein are non-limiting examples and are merely examples among other possible examples. 
     A private cellular network within the context of the present disclosure is an ecosystem comprised of a backend component (a cloud component) and a site component. A site component may be comprised of specially configured hardware components installed at a site to provide cellular network (voice and data) connectivity to endpoints connected thereto. 
     A site component can be comprised of a number (e.g., ranging from single digit numbers to hundreds or thousands) of radio access components (e.g., small cell radio components that provide network connectivity such as LTE small cells, 5G access nodes, etc.) that are deployed over a limited geographical area (e.g., a building, a factory floor, a neighborhood, a shopping mall, etc.) and operate over a spectrum available for private use. The site component further includes known or to be developed radio equipment such as routers and core network components (Evolved Packet Core (EPC) components). EPC components can be 4G/LTE EPC components and/or 5G EPC components/functionalities. 
     For example, 4G/LTE EPC components include, but are not limited to, a Serving GPRS Support Node (SGSN), Gateway GPRS Support Node (GPRS) Mobile Switching Center (MSC), a Mobility Management Entity (MME), Home Subscriber Server (HHS), a Serving Gateway (S-GW), a Packet Data Network Gateway (PDN-GW), a Policy &amp; Charging Rules Function (PCRF). 
     In another example, 5G EPC components include, but are not limited to, a Authentication Server Function (AUSF), a Core Access and Mobility Management Function (AMF), a Data network (DN), a Structured Data Storage network function (SDSF), an Unstructured Data Storage network function (UDSF), a Network Exposure Function (NEF), a NF Repository Function (NRF), a Policy Control function (PCF), a Session Management Function (SMF), a Unified Data Management (UDM), a User plane Function (UPF), an Application Function (AF), etc. Components of a 5G core can be referred to as functionalities as most are software based and can be adapted according to need and use case. 
     The site component can also include IP Multimedia Subsystem (IMS) for delivering IP multimedia services such as Voice over LTE (Vo-LTE) through IMS core. IMS core can handle IMS functionalities including, but not limited to, subscriber management, session setup and policy and charging enforcement, maintaining Quality of Service (QoS) and seamless interfacing between IMS Application Servers and the EPC. 
     The backend (cloud) component may provide one or more EPC functionalities (e.g., HSS services), manage interfacing and communication of the private cellular network with MNOs, allow mobility among users of the private cellular network by enabling them to move between multiple site components and still access their home site component, etc. Services provided by the backend component may be shared by/segmented for use by multiple private cellular networks that function independently as they may have been deployed at different sites and operated by different/independent enterprises. Additionally, the backend component may include networking and management tools (Network as a Service (NaaS)) built and deployed over network components (e.g., NaaS developed by Geoverse LLC of Seattle, Wash.) that are trusted by operators of the private cellular networks and various mobile network operators (MNOs) that, as will be described below, have suboptimal coverage in these confined geographical locations and thus have their endpoints and subscribers roam on such private cellular networks. 
     Such ecosystems, as described above, offer a fully interconnected private cellular network with a number of significant advantages to enterprises and MNOs. These ecosystems are flexible and scalable and eliminate costs and complexities associated with enterprises having to develop their own private network capabilities and/or costs and complexities associated with MNOs having to expand their network infrastructure and services to provide cellular connectivity to their subscribers and endpoints. 
     A fully integrated ecosystem described above provides premium connectivity services to both home and guest (roaming) devices coupled with various analytical features such as end user experience, service usages, indoor location determination and indoor mapping as well as capacity monetization including, but not limited to, potential sale of excess capacity to mobile operators and others. 
     Premium connectivity services include, but are not limited to, Subscriber Identity Module (SIM) subscriptions, shared data bundles, private cellular (LTE) voice, edge computing capabilities, etc. home and guest (roaming) devices include, but are not limited to, bridges, gateways, modems, push-to-talk devices, smartphones, tablets, laptops, Internet of Things (IoT) devices such as facility management devices, HVAC control devices, security monitoring devices, point of sale devices, sensors for maintenance, asset tracking, etc., robotics and autonomous vehicles, etc. 
     Cellular connectivity and services may be provided to guest devices by the private cellular network where the cellular connectivity services of the devices&#39; home networks may be sub-optimal/less than a threshold level of service. Such threshold level of service may be a configurable parameter determined based on experiments and/or empirical studies. For example, when cellular data services offered by a home network is less than a threshold download/upload speed (in mbps) or such services of slower than same services provided by private cellular network by more than a threshold percentage (e.g., slower by more than 5%, 10%, 20%, etc.), private cellular network may be utilized to provide better cellular voice and data services to end users and thus improve end user experience. In addition to download/upload speed, other examples of such thresholds include signal strength (received signal strength indicator), signal quality measurement(s), etc. 
       FIG. 1  illustrates an overview of a private cellular network ecosystem, according to an aspect of the present disclosure. In ecosystem  100 , one or more Mobile Network Operators (MNOs)  102  may interface with private cellular network of the present disclosure, which is comprised of a cloud based backend component  104  and site component  106 . 
     MNOs  102  may include, but are not limited to, known operators of cellular networks such as AT&amp;T®, Verizon®, T-Mobile®, Sprint®, Charter Spectrum®, Xfinity Mobile®, Vodafone® and/or any other known or to be established MNO. In one example, MNOs  102  may have a number of subscribers that may visit site component  106 , in which the corresponding MNO(s) may not have sufficient wireless coverage and services available to their subscribers. As will be described below, these subscribers may roam on private cellular network at site component  106  when a roaming agreement is in place and is active between provider of the private cellular network at a site and roaming subscribers&#39; respective MNOs. 
     Use of the private cellular network described in the present application is not limited to MNO subscribers with home MNOs having an active roaming arrangement in place with the provider of the private cellular network. For example, the private cellular network may be accessed by any mobile device having a dual-SIM capabilities with one SIM card being registered with their home MNO (cellular service provider) and another SIM card registered with the private cellular network. Another example use of private cellular network may be as part of a Multi-Operator Core Network (MOCN) structure, where one or more MNOs and private cellular network of the present disclosure may share the network infrastructure (e.g., edge or metro core router, as will be described below) of the private cellular network for servicing their subscribers. 
     Backend component  104  may include, but is not limited to, Multi-Protocol Label Switching (MPLS) cloud  108  on which one or more EPCs  110  of the private cellular network (e.g., located in different physical locations/cities) are accessible. Various known, or to be developed, cloud services  112  as well as the Internet  114  are also accessible via cloud  108 . 
     Site component  106  of  FIG. 1  includes two non-limiting examples of a metro site and an edge site. As noted above, a site component may include specially configured hardware components that provide network connectivity (cellular voice and data) to connected endpoints. 
     A metro site component may be deployed in a metropolitan area such that the private cellular network can encompass several/independent confined geographical areas such as a shopping mall comprised of multiple independent stores and locations, one or more blocks of a city, an entire university campus, etc. In  FIG. 1 , an example metro site is comprised of sites  116  and  118 . Example site  116  can be an open air strip mall while example site  118  can be a closed building such as shopping mall. Access points  120  may be installed throughout sites  116  and  118  and communicate via Internet  122  (e.g., over known or to be developed Virtual Private Network (VPN) and IP security (IPSec) connections and protocols) with a private cellular edge formed of a metro core router  124  and a metro EPC  126 . Metro core router  124  may be connected to MPLS cloud  108  and cloud backend component  104  via any known or to be developed wired and/or wireless connection (e.g., a 1G or a 10G connection). 
     An edge site component may be deployed in a single location providing cellular connectivity to users of and roamers associated with a single entity (e.g., a single corporation or business entity) and covers a confined geographical area that is smaller and more limited compared to a metro site. Another distinction between an edge site component and a metro site component is that each edge site is equipped with a dedicated edge core router and edge EPC (serving a single entity or enterprise network of a corporation, etc.) while several components of a metro site component may be shared by connected endpoints of several different entities as they share the same metro core router and metro EPC as described above. 
     Example edge sites component  128  of  FIG. 1  may be at a factory site with a dedicated edge core router  130  and a dedicated edge EPC  132 . Edge site component  128  may also have one or more access points  134  installed throughout the site and communicatively connected to edge core router  130  and edge EPC  132 . 
     Example edge site component  136  may be a building with a dedicated edge core router  138  and a dedicated edge EPC  140 . Edge site component  136  may also have one or more access points  142  installed throughout the site and communicatively connected to edge core router  138  and edge EPC  140 . 
     Each of edge core routers  130  and  138  may be communicatively connected to MPLS cloud  108  and cloud backend component  104  via known or to be developed connections such as a VPN connection, a wired 1G/10G connection, etc. 
     Edge core routers  130 ,  138  a metro core router  124  may also be referred to as proxy routers. 
       FIG. 2  illustrates an overview of an edge site component of a private cellular network deployed at an edge site, according to an aspect of the present disclosure. Edge site component  200  of  FIG. 2  may be the same as edge site component  136  of  FIG. 1  with a dedicated edge core router  202  and a dedicated edge EPC  204  that may be the same as dedicated edge core router  138  and edge EPC  140 , respectively. An enterprise network may be deployed in a building (edge site/customer site)  206  or a portion thereof occupied by an organization, entity, etc., Such enterprise network may be coupled to edge site component  200  so that edge site component  200  can provide private cellular network connectivity to endpoint devices of the enterprise network and/or any one or more external devices (not registered or part of enterprise network) present at edge site  206  and for which their corresponding MNO has an agreement in place with operator of edge site component  200  or otherwise is considered a valid UE/data source as described above and will be described further below. 
     The enterprise network may have one or more enterprise specific endpoints such as Private Branch Exchange (PBX) devices  208 . PBX devices  208  may form a private telephone network of an organization associated with the enterprise network at edge site  200 . Other examples of enterprise specific endpoints include, but are not limited to, mobile device  210 , one or IoT devices (not shown), tablets, laptops, desktops, switches, routers, etc. (not show). 
     In example of  FIG. 2 , mobile device  210  may be a device registered with the enterprise network and the private cellular network provider. Accordingly, mobile device  210  may be provided with a SIM card registered with the private cellular network provided via edge site component  200 . Mobile device  210  may be referred to as home mobile device  210  for which the private cellular network deployed at edge site  200  serves as the primary cellular service provider. Accordingly, mobile device  210  may connect to edge core router  202  and subsequently to the rest of the private cellular network to receive voice (e.g., LTE/5G quality voice (VoLTE)) and cellular data services. Furthermore, any one or more roaming/guest devices may roam on the private cellular network provided via edge site component  200 , as will be described above. Such roaming/guest devices may not have a SIM card registered with private cellular network provided by edge site component  200  and instead may be registered with one or more of MNOs described above with reference to  FIG. 1 , serving as corresponding home cellular network providers of the roaming/guest devices. 
     Also, shown in  FIG. 2  is an example of another home mobile device  212  that is registered with the private cellular network deployed via edge site component  200 . However, mobile device  212  may be located outside building/site  206  such that mobile device  212  no longer falls within footprint/coverage area of the deployed private cellular network. Mobile device  212  can fall within the footprint of a cellular base  214  (e.g., LTE base station, eNode-B, etc.) of an MNO, examples of which are described above with reference to  FIG. 1 . Mobile device  212  can then connect to cellular base  214  and to edge EPC  204  to receive cellular voice and data services. 
       FIG. 3  illustrates details of cloud and site components of ecosystem of a private cellular network, according to an aspect of the present disclosure. As described above with reference to  FIGS. 1 and 2  as well, ecosystem  300  is comprised of backend component  302  and site component  304 , which may be the same as backend component  104  and site component  106  of  FIG. 1 , respectively. Backend component (cloud component)  302  and site component  304  may form a private cellular network configured to provide cellular voice and data services to one or more home devices of an enterprise network (at a customer site) that is communicatively coupled to site component  304 . 
     In addition to backend component  302  and site component  304 ,  FIG. 3  also illustrates, in general, components of MNOs and an example enterprise network communicatively coupled to cloud component  302  and site component  304 , respectively, and will be further described below. 
     Site component  304  may have one or more access points  306  (e.g., a Citizens Broadband Radio Service (CBRS) access point) coupled to an edge core router  308 , all of which may be deployed at a customer site, which can be the same as edge site  206  of  FIG. 2 . 
     Edge core router  308 , as will be described below, is a specially configured router for managing network traffic (inbound and outbound) to and from connected endpoints such as endpoints  309 ,  310  and  311  (each of which may also be referred to as a user equipment (UE)). A number of UEs connected to private cellular network at the customer site is not limited to 3 and can be more or less. 
     UEs  309 ,  310  and  311  can be any one of, but not limited to, a mobile device, a tablet, a laptop, an Internet of Things (IoT), a sensor, etc. In other words, UEs  309 ,  310  and  311  can be any device capable of establishing a wireless/cellular connection to nearby device. 
     As will be further described below, any number of UEs may be registered with enterprise network  313 . Furthermore, one or more of UEs  309 ,  310  and  311  may be roaming devices that are not registered with enterprise network  313  but instead are associated with MNOs that have roaming agreements in place with provider of private cellular network at the customer site and hence are allowed to roam on the private cellular network. 
     One or more of UEs  309 ,  310  or  311  may also be a dual-SIM device registered with both a home MNO and private cellular network without the MNO necessarily having a roaming arrangement in place with the private cellular network. In another example, any one or more of UEs  309 ,  310  or  311  may be a subscriber of an MNO being part of a MOCN with private cellular network of the present disclosure. All such UEs may be considered valid UEs (which may also be referred to as a valid source of a data packet) that may access private cellular network of the present disclosure and have core router of the private cellular network service (route) their respective inbound/outbound voice and data traffic. 
     Accordingly and while example embodiments are primarily described with reference to a roaming UE with a home MNO that has an active roaming agreement in place with the provider of private cellular network of the present application, as an example of a valid UE, the present disclosure is not limited thereto. A valid UE may also be a dual-SIM UE or a UE of a subscriber with an MNO that is part of a MOCN with the private cellular network. Similarly, the present disclosure may frequently refer to services provided by the private cellular network and edge core router  308  to a valid UE as roaming services. Such services are not limited to roaming services commonly referred to in the relevant art but may also include secondary/auxiliary LTE services. Accordingly, services provided by private cellular network of the present disclosure may be referred to as complimentary (and/or secondary or auxiliary) cellular services. 
     Edge core router  308  may be coupled to edge EPC  312  (e.g., via a S1 LTE connection shown in  FIG. 3 ). In example of  FIG. 3 , edge EPC  312  also provides IMS services described above. Edge EPC  312  may be configured to manage user plane traffic of private cellular users (e.g., user equipment and connected endpoints of enterprise network  313  for which the private cellular network serves as a home cellular service provider). Edge EPC  312  may interface with enterprise Local Area Network (LAN)  314  to handoff user plane traffic to enterprise network  313  (with layer 3/layer 2 option). An example connection between edge EPC  312  and enterprise network  313  may be via a SGi interface/connection as shown in  FIG. 3 . Enterprise network  313  may include enterprise equipment and devices such as enterprise LAN  314  and enterprise PBX  315  described above. 
     Site component  304  may further include a firewall  316  that interfaces with access point  306 , edge core  308 , edge EPC  312 , with access point  306  and components of enterprise network  313 . As shown in  FIG. 3 , firewall  316  may interface with access point  306  via a dedicated S1 interface (or a 5G N2 interface, if the private cellular network is a 5G network). Firewall  316  may interface with edge core router  308  via another dedicated  51  connection and Simple Network Management Protocol (SNMP) protocol. Firewall  316  may interface with edge EPC  312  via S6a and S8 connections and Simple Network Management Protocol (SNMP). Furthermore, firewall  316  may be connected to enterprise LAN  314  via a SGi connection. 
     Backend component  302  may be communicatively connected to site component  304  via any known or to be developed secure communication medium such as a secure VPN connection  318 . 
     Backend component  302  may include a backbone  320  and communicatively coupled to one or more cloud based servers (may be geographically distributed) and may be proprietary or provided via third party providers of private/public/hybrid cloud infrastructure. Any one or more of such cloud based servers may be a HSS server  322  configured to authenticate SIM cards associated with the private cellular network (e.g., a SIM card activate in UE  310 ) and/or a SIM card of an MNO with an associated UE roaming on the private cellular network at the customer site shown in  FIG. 3  and similarly described in  FIG. 2 . Another one of such servers may be a cloud EPC  324 . Cloud EPC  324  may function to direct home traffic originating from one site component such as site component  304  to another site component of the same private cellular network. For example, an organization may have offices in multiple cities, all of which may be operating on enterprise network  313 . Site component  304  of the private cellular network may be deployed at each one of the multiple offices. Accordingly, local cellular traffic from one site component  304  at one of the offices may be directed to the private cellular network deployed at another office via cloud EPC  324 . 
     Backend component  302  may also include an IP Multimedia Service (IMS)  325  for communicating/processing requests for IMS services to appropriate IMS processing components of home networks. IMS  325  may also process/forward requests for emergency services (e.g., 911 services) to appropriate providers of such services such as emergency services  327 . 
     Backend component  302  may further include an additional server  326  that may be referred to as Network Operation Center (NOC)  326  configured to manage operation of the private cellular network ecosystem and provide NaaS services described above and services such as network monitoring, customer service, etc. 
     Backbone  320  may be communicatively coupled to HSS  322  via a S6a connection, to cloud EPC  324  via an S1 interface, to IMS  325  via any known or to be developed communication scheme/protocol and to NOC  326  via an SNMP protocol. 
     As also shown in  FIG. 3 , backbone  320  may be connected/communicatively coupled to multiple MNOs.  FIG. 3  illustrates an example of three different MNOs, each of which has a corresponding MNO EPC from among the three examples of MNO EPCs  328 . Each MNO EPC from MNO EPCs  328  may optionally have a corresponding MNO IMS from among MNO IMSs  330  shown in  FIG. 3 . Alternatively, multiple MNO EPCs  328  may share a common MNO IMS  330 . A combination of one MNO EPC  328  and one MNO IMS  330  may be referred to as an MNO. 
     Furthermore, each MNO EPC  328  may be communicatively coupled to a cell tower such as cell tower  307 . While  FIG. 3  illustrates a single cell tower  307 , each MNO may have a separate cell tower similar to cell tower  307  to which it is communicatively coupled. In the non-limiting example of  FIG. 3 , a single tower  307  may be shared by all MNOs formed by MNO EPCs  328  and MNO IMSs  330 . 
     Cell tower  307  is intended to provide cellular and voice data coverage to one or more subscribers such as UEs  309 ,  310  and/or  311 . However, for various reasons, such coverage may be limited or unavailable to UEs  309 ,  310  and/or  311 . For example, coverage of a given MNO may be weak or otherwise not allowed inside the geographical location (customer site) in which the enterprise LAN  314  and the private cellular network is deployed, hence a corresponding one of UEs  309 ,  310  or  311  may be operating as a guest device on the private cellular network. 
     A given MNO comprised of one of MNO EPCs  328  and optionally one of MNO IMSs  330  may operate as home network of one or more UEs (e.g., UEs  309 ,  310  and  310 ) roaming on the private cellular network provided by backend component  302  and site component  304  at the customer site (e.g., because coverage of the home network within the site in which the private cellular network is deployed, may be suboptimal (less than a threshold coverage)). Connection between backbone  320  and MNO networks  328  may be via any known or to be developed communication link such as roaming links (S8 interface) and IPX connections. 
     With example overview and structure of a private cellular network described above with reference to  FIGS. 1-3 , one or more example processes will be described with reference to  FIGS. 4-7  according to which intra-network roaming at various deployment locations associated with a private cellular network may be implemented. 
       FIG. 4  is a visual representation of an example of intra-network roaming and traffic routing via edge core router of a private cellular network, according to an aspect of the present disclosure. Elements in  FIG. 4  that are the same as their corresponding counterpart in  FIG. 3  are numbered the same as in  FIG. 3  and will not be further described for sake of brevity. For example, access point  306  in  FIG. 4  is the same as access point  306  in  FIG. 3  and will not be further described with reference to  FIG. 4 . 
     In ecosystem  400  of  FIG. 4 , UEs  309 ,  310  and  311  may be communicatively connected to access point  306  (e.g., eNode-B  306 ). In the context of  FIG. 4 , each of UEs  309 ,  310  and  311  may be associated with a different organization and each organization may have an organization-configured private cellular network (e.g., provided and operated by private cellular service provider of example systems described with reference to  FIGS. 1-3 ) installed at one or more locations of that organization. In another example, UEs  309 ,  310  and  311  may be associated with the same organization but different branches, offices and/or locations thereof. An organization may have independently configured instances of the private cellular network for each of its branches, offices and/or locations with corresponding on premise deployment of access point(s), edge core router(s), and/or edge EPC(s) installed at each branch, office and/or location. In this instance, UE  309  from one office may operate on a home instance of the private cellular network while at the home office of a user associated with UE  309  but may roam as a visiting device on another instance of the private cellular network while visiting another office of the same organization. Alternatively, organization may configure the private cellular network on an organization-wide basis such that all offices, branches and/or locations are home locations and all devices associated with the organization operate on the deployed private cellular network as home devices regardless of the office, branch and/or location at which such devices are located. 
     In example of  FIG. 4 , it is assumed that UE  309  is a device associated with organization A, UE  310  is a device associated with organization B and UE  311  is a device associated with organization C. Furthermore, it is assumed that access point  306  is installed at or near a location (e.g., office) associated with organization A and communicatively coupled to edge core router  308  and edge EPC  312  installed on premise at the location associated with organization A. Moreover, it is assumed that UEs  309 ,  310  and  311  are communicatively coupled to access point  306  and that each of organizations B and C have a separately configured private cellular network installed at their own respective location(s). Therefore, UEs  310  and  311  may be said to be roaming on the private cellular network available at the location associated with organization A in which access point  306 , edge core router  308  and/or edge EPC  312  are installed. Each of organizations B and C may have their own respective edge EPC, to which network traffic to and from UEs  310  and  311  may be routed via edge core router  308 , as will be described below. While having their own respective private cellular network, each of organizations A, B and C may be a customer of the provider of the private cellular network. 
     Box  402  in  FIG. 4  includes UEs  309 ,  310  and  311  as well as on premise components of the private cellular network deployed at the location associated with organization A. The components include, but are not limited to, access point  306 , edge core router  308 , edge EPC  312 , enterprise network  314 , etc. Edge EPC  312  includes any known or to be developed component including MME  404 , S-GW  405 , P-GW  407 , etc. Box  402  also includes enterprise network  313 . 
       FIG. 4  provides a different illustration of edge core router  308  compared to  FIG. 3 . More specifically, one or more interfaces/internal components of edge core router  308  are shown in  FIG. 4  including S1 In server  401 - 1  configured to receive connection/data requests and network traffic to and/or from various end devices connected thereto (e.g., UEs  309 ,  310  and  311 ) via access point  306 . Edge core router  308  may further include client interfaces (may simply be referred to as clients) such as S1 client  401 - 2  and S1 client  401 - 2  for managing and directing traffic to appropriate edge EPC/home network of the device (e.g., UE  310  and/or UE  311 ) from which a communication is received, as will be further described below. 
     Each of UEs  309 ,  310  and  311  may have an identifier, which may be referred to as an Intentional Mobile Subscriber Identity (IMSI) number. An IMSI number may be a 15-digit number that includes a three digit Mobile Country Code (MCC), a three digit Mobile Network Code (MNC) and a nine digit Mobile Subscriber Identification Number (MSIN). Each device such as UEs  309 ,  310  and/or  311  may have an IMSI issued by the provider of the private cellular network to which respective organizations A, B and C associated with UEs  309 ,  310  or  311  have subscribed, thus designating each of UEs  309 ,  310  and/or  311  as devices registered with the private cellular network. Such IMSI number can uniquely associate the respective UE to the private cellular network subscribed to and deployed at their respective organization&#39;s office(s), location(s), etc. For example, the nine digit MSIN of respective IMSIs of UEs  309 ,  310  and  311  may be issued by the private cellular network service provider that can uniquely associate each of UEs  309 ,  310  and/or  311  with the private cellular network to which their respective organizations has subscribed. 
     As shown in  FIG. 4 , incoming traffic from any one of UEs  309 ,  310  and  311  may be analyzed by core router  308 . More specifically, core router  308  may have a table of IMSIs. Such table (list) may identify “home” IMSIs and may also be referred to as an IMSI whitelist. Home IMSIs may be defined as IMSIs corresponding to devices registered with the private cellular network deployed at location of organization A (e.g., devices associated with a specific location of organization A at which access point  306 , core router  308  and/or edge EPC  312  are installed, and/or with organization A in general). Traffic from devices with “Guest” IMSIs may be appropriately routed to their corresponding home EPC via S1 interface  401 - 3 , as will be described below. 
     For instance, UE  309  associated with organization A at a location at which access point  306 , edge core router  308 , edge EPC  312  and/or enterprise network  314  are deployed (on premise deployment), may connect to access point  306 . Once connected, edge core router  308  may recognize an IMSI associated with UE  309  and determine that the IMSI of UE  309  is in the whitelist of home IMSIs. Accordingly, via S1 interface  401 - 2 , edge core router  308  routes the traffic of UE  309  to edge EPC  312  and subsequently to enterprise network  314 . Example router of network traffic to and/or from UE  309  to on premise network is shown using line  406 . 
     Furthermore, UEs  310  and/or  312  may also be on premise at location of organization A (each of UEs  310  and/or  311  may have their own IMSIs associated with the private cellular network deployed and operation at their own respective location(s) and organization(s)). After UE  310  and/or UE  311  establish a connection to access point  306 , edge core router  308  may identify IMSI of UE  310  and/or IMSI of UE  311  and determine that neither IMSI belongs to the whitelist of home IMSIs at the location of organization A. Accordingly, using S1 interface  401 - 3  (may also be referred to as the default route), connections to and/or from UEs  310  and  311  may be sent to a common EPC. In instances of a 5G private network, an N2 interface may be used instead of S1 interface  401 - 3 . Common EPC  412  may operate as a hub routing point between core router (e.g., core router  308 ) of a visited private cellular network and the home network of each roaming device on the visited network (e.g., UEs  310  and  311 ). Without common EPC  412 , such routing of network traffic between a roaming UE such as UEs  310  and  311  and their respective home networks would have to be a one-to-one (i.e., core router  308  to a dedicated EPC of each home network), which would create a mesh that grows as the number of visiting UEs on a private cellular network (e.g., private cellular network  314 ). Maintenance of such mesh can consume significant amount of resources. A common EPC such as common EPC  412  disclosed here, would address the issue and hence avoids the resources and costs needed for a maintaining a one-to-one network connectivity with home network specific EPCs. 
     In response, common EPC  412  (which can include any known or to be developed EPC component including, but not limited to, MME  414  and S-GW  416 ) may determine the home network of each of UEs  310  and  311 . For example, in  FIG. 4 , home network of UE  310  is shown using box  418  and home network of UE  311  is shown using box  420 . Home network of UE  310  may include a corresponding P-GW  422  and Internet  424  (e.g., internet access for UE  310  when organization B associated with UE  310  has no organization specific enterprise network deployed and operational). Home network of UE  311  may include a corresponding P-GW  426  and enterprise network  428 . In one example, common EPC  412  may identify the home network of either UE  310  or UE  311  using UE  310 &#39;s and/or UE  311 &#39;s Access Point Name (APN). For example, MME  414  may perform a DNS query to find IP address of P-GW of home network of UE  310  and/or UE  311  based on the APN of the corresponding one of UE  310  or UE  311 . 
     In some examples, home EPC of UE  310  and  311  may each have an S8 interface (i.e., S5 interface shown in  FIG. 4  between S-GW  416  of common EPC  412  and P-GW  422  of home network  418  of UE  310 , may be replaced with an S8 interface. Similarly, S5 interface shown in  FIG. 4  between S-GW  416  of common EPC  412  and P-GW  422  of home network  418  of UE  310 , may be replaced with an S8 interface) for receiving corresponding network traffic from common EPC  412 . Furthermore, private cellular network provider of  FIG. 4  that operate components shown in box  402  and to which UEs  309 ,  310 , and  311  are connected, may operate a virtual private network (VPN) between common EPC  412  and each respective home EPC (e.g., between S-GW  416  and each of P-GWs  422  and  426 ). These example VPNs are illustrated as components  450  and  452  in  FIG. 4   
     As shown in  FIG. 4 , the traffic route to and/or from UE  310  via edge core router  308  is shown using line  406  while the traffic route to and/or from UE  310  via edge core router  308  is shown using line  408 . 
       FIG. 5  is a visual representation of another example of intra-network roaming and traffic routing via edge core router of a private cellular network, according to an aspect of the present disclosure. Elements in  FIG. 5  that are the same as their corresponding counterpart in  FIG. 4  are numbered the same as in  FIG. 4  and will not be further described for sake of brevity. For example, access point  306  in  FIG. 5  is the same as access point  306  in  FIG. 4  and will not be further described with reference to  FIG. 5 . 
     In the example of  FIG. 4 , edge core router  308  has to S1 interfaces, S1 interface  401 - 2  for local traffic to on premise edge EPC  312  and another default route via S1 interface  401 - 3  to non-local edge EPCs. In contrast, edge core router of  FIG. 5  may have one or more dedicated interfaces for network traffic to and/or from devices associated with various Mobile Network Operators (MNOs) that may have partnered with provider of the private cellular network described above. 
     In example ecosystem  500  in  FIG. 5 , UE  309  and management/routing of traffic thereof to and/or from on premise edge EPC  312  is the same as that described above with reference to  FIG. 4 . Furthermore, UE  311  and management/routing of traffic thereof to and/from UE  311 &#39;s remote edge EPC  426  (via S1 interface  401 - 3  of edge core router  508  and common EPC  412 ) is the same as that described above with reference to  FIG. 4 . 
     Example ecosystem  500  of  FIG. 5  also includes UEs  502 ,  504  and  506 , each of which may be associated with a different MNO (e.g., UE  502  may be associated with Verizon, UE  504  may be associated with AT&amp;T and UE  506  may be associated with T-Mobile). Verizon, AT&amp;T and T-Mobile can be examples of MNOs associated with/partnered with provider of private cellular network of  FIGS. 1-5 . In another example, an MNO can be an independent private cellular network provided by another private cellular network provider. 
     On edge core router  508  of  FIG. 5 , each MNO partner may have a dedicated S1 interface. For example, S1 interface  508 - 1  may be associated with MNO partner of which UE  502  is a subscriber (e.g., Verizon). S1 interface  508 - 2  may be associated with MNO partner of which UE  504  is a subscriber (e.g., AT&amp;T). S1 interface  508 - 3  may be associated with MNO partner of which UE  506  is a subscriber (e.g., T-Mobile). 
     Edge core router  508  may be configured with Public Land Mobile Network (PLMN) number for each network for which there is a dedicated S1 interface on edge core router  508 . A PLMN can be a six digit number formed of MCC (three digits) and MNC (three digits), as described above. Private cellular network with on premise deployment at location of organization A may have an associated PLMN as shown (e.g.,  310330 ). PLMN for UEs  309  and  311  can be the same since both devices are associated with different instances of the private cellular network provided by the provider. Each of MNOs associated with UEs  502 ,  504  and  506  may have a corresponding PLMN (e.g., shown as Partner A, Partner B and Partner C on server  401 - 1  in  FIG. 5  as an example but in practice would be a six digit number each). 
     In one example, server  401 - 1  of edge core router  508  can advertise configured PLMNs to access point  306 . Upon detecting a connection to access point  306  by each of UEs  309 ,  311 ,  502 ,  504  and/or  506 , each device may request using connection via the private cellular network. Accordingly, traffic from each such device with established connection to edge core router  508  can be managed and routed via the appropriate one of S1 interfaces after edge core router  508  examines the IMSI of each device. If such IMSI is in a whitelist (e.g., as described above with reference to  FIG. 4 ), then the traffic is routed to on premise edge EPC  312  via S1 interface  401 - 2 . If an IMSI corresponds to one of UEs  502 ,  504  and//or  506 , then corresponding traffic is routed to home network of the corresponding MNO via the corresponding dedicated S1 interface (e.g., S1 interface  508 - 1 ,  508 - 2  and/or  508 - 3 ). Lastly and as described above with reference to  FIG. 4 , network traffic to and/or from UE  311  roaming on private cellular network at location of organization A can be routed via default router of S1 interface  401 - 3  to common EPC  412  and subsequently to remote operator network  522 . 
       FIG. 5  illustrates the traffic routing of traffic to and/or from each device connected to access point  306  using lines  406 ,  410 ,  510 ,  512  or  514 . For example, line  406  shows traffic routing for UE  309  to edge EPC  312  as described above with reference to  FIG. 4 . Similarly, line  410  shows traffic routing for UE  311  to remote operator network  522  (e.g., P-GW  524  of the remote edge EPC and internet  526 ), in a similar manner as described above with reference to  FIG. 4 . Line  510  shows traffic routing for UE  502  to corresponding home MNO  516  (including home EPC) via S1 interface  508 - 1 . Line  512  shows traffic routing for UE  504  to corresponding home MNO  518  (including corresponding home EPC) via S1 interface  508 - 2 . Line  514  shows traffic routing for UE  506  to corresponding home MNO  520  (including corresponding home EPC) via S1 interface  508 - 3 . 
       FIG. 6  illustrates an example process for managing network traffic in a private cellular network according to an aspect of the present disclosure.  FIG. 6  embodies the process of routing network traffic as described above with reference to  FIGS. 4 and 5 . 
     At S 600 , router  308  (or similarly router  508 ) receive network traffic from one or more connected endpoints (e.g., one of UEs  309 ,  310 ,  311 ,  502 ,  504 , and/or  506 ). In one example, the network traffic may be received via access point  306 . 
     At S 602 , router  308  identifies each UE from which the network traffic is received as any one of an endpoint registered with the private cellular network and for which the router and an associated edge evolved packet core deployed at a location, serve as a home network, a roaming endpoint roaming on the private cellular network that is associated with an MNO such as one of UEs  502 ,  504 , and/or  506 , or a roaming endpoint roaming on the private cellular network. This identifying process may be performed as described above with reference to  FIGS. 4 and 5 . 
     At S 604 , router  308  routes the corresponding network traffic for each connected endpoint either to edge EPC  312  of the private cellular network (if the router  308  and edge EPC  312  operate as the home network), to an evolved packet core of the corresponding MNO (via the corresponding dedicated S1-interface on router  308  as described above with reference to  FIG. 5 ), or to a corresponding home EPC of a visiting endpoint via the dedicated S1-interface (e.g., S1-interface  401 - 3 ) and common EPC  412  as described above with reference to  FIGS. 4 and 5 . 
     With various examples of traffic management and routing at a core router of a private enterprise network deployed at a site described above, the disclosure now turns to description of several example system components and architectures that can be utilized to function as any one or more components of ecosystems described above such as edge core router  308 , metro core router  124 , etc. 
       FIGS. 7A and 7B  illustrate systems according to an aspect of the present disclosure. The more appropriate system will be apparent to those of ordinary skill in the art when practicing the various embodiments. Persons of ordinary skill in the art will also readily appreciate that other systems are possible. 
       FIG. 7A  illustrates an example of a bus computing system  700  wherein the components of the system are in electrical communication with each other using a bus  705 . The computing system  700  can include a processing unit (CPU or processor)  710  and a system bus  705  that may couple various system components including the system memory  715 , such as read only memory (ROM)  720  and random access memory (RAM)  725 , to the processor  710 . The computing system  700  can include a cache  712  of high-speed memory connected directly with, in close proximity to, or integrated as part of the processor  710 . The computing system  700  can copy data from the memory  715 , ROM  720 , RAM  725 , and/or storage device  730  to the cache  712  for quick access by the processor  710 . In this way, the cache  712  can provide a performance boost that avoids processor delays while waiting for data. These and other modules can control the processor  710  to perform various actions. Other system memory  715  may be available for use as well. The memory  715  can include multiple different types of memory with different performance characteristics. The processor  710  can include any general purpose processor and a hardware module or software module, such as services (SVC)  1   732 , SVC  2   734 , and SVC  3   736  stored in the storage device  730 , configured to control the processor  710  as well as a special-purpose processor where software instructions are incorporated into the actual processor design. The processor  710  may essentially be a completely self-contained computing system, containing multiple cores or processors, a bus, memory controller, cache, etc. A multi-core processor may be symmetric or asymmetric. 
     To enable user interaction with the computing system  700 , an input device  745  can represent any number of input mechanisms, such as a microphone for speech, a touch-protected screen for gesture or graphical input, keyboard, mouse, motion input, speech and so forth. An output device  735  can also be one or more of a number of output mechanisms known to those of skill in the art. In some instances, multimodal systems can enable a user to provide multiple types of input to communicate with the computing system  700 . The communications interface  740  can govern and manage the user input and system output. There may be no restriction on operating on any particular hardware arrangement and therefore the basic features here may easily be substituted for improved hardware or firmware arrangements as they are developed. 
     The storage device  730  can be a non-volatile memory and can be a hard disk or other types of computer readable media which can store data that are accessible by a computer, such as magnetic cassettes, flash memory cards, solid state memory devices, digital versatile disks, cartridges, random access memory, read only memory, and hybrids thereof. 
     As discussed above, the storage device  730  can include the software SVCs  732 ,  734 , and  736  for controlling the processor  710 . Other hardware or software modules are contemplated. The storage device  730  can be connected to the system bus  705 . In some embodiments, a hardware module that performs a particular function can include a software component stored in a computer-readable medium in connection with the necessary hardware components, such as the processor  710 , bus  705 , output device  735 , and so forth, to carry out the function. 
       FIG. 7B  illustrates an example architecture for a chipset computing system  750  that can be used in accordance with an embodiment. The computing system  750  can include a processor  755 , representative of any number of physically and/or logically distinct resources capable of executing software, firmware, and hardware configured to perform identified computations. The processor  755  can communicate with a chipset  760  that can control input to and output from the processor  755 . In this example, the chipset  760  can output information to an output device  765 , such as a display, and can read and write information to storage device  770 , which can include magnetic media, solid state media, and other suitable storage media. The chipset  760  can also read data from and write data to RAM  775 . A bridge  780  for interfacing with a variety of user interface components  785  can be provided for interfacing with the chipset  760 . The user interface components  785  can include a keyboard, a microphone, touch detection and processing circuitry, a pointing device, such as a mouse, and so on. Inputs to the computing system  750  can come from any of a variety of sources, machine generated and/or human generated. 
     The chipset  760  can also interface with one or more communication interfaces  790  that can have different physical interfaces. The communication interfaces  790  can include interfaces for wired and wireless LANs, for broadband wireless networks, as well as personal area networks. Some applications of the methods for generating, displaying, and using the technology disclosed herein can include receiving ordered datasets over the physical interface or be generated by the machine itself by the processor  755  analyzing data stored in the storage device  770  or the RAM  775 . Further, the computing system  750  can receive inputs from a user via the user interface components  785  and execute appropriate functions, such as browsing functions by interpreting these inputs using the processor  755 . 
     It will be appreciated that computing systems  700  and  750  can have more than one processor  710  and  755 , respectively, or be part of a group or cluster of computing devices networked together to provide greater processing capability. 
     For clarity of explanation, in some instances the various embodiments may be presented as including individual functional blocks including functional blocks comprising devices, device components, steps or routines in a method embodied in software, or combinations of hardware and software. 
     In some example embodiments the computer-readable storage devices, mediums, and memories can include a cable or wireless signal containing a bit stream and the like. However, when mentioned, non-transitory computer-readable storage media expressly exclude media such as energy, carrier signals, electromagnetic waves, and signals per se. 
     Methods according to the above-described examples can be implemented using computer-executable instructions that are stored or otherwise available from computer readable media. Such instructions can comprise, for example, instructions and data which cause or otherwise configure a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. Portions of computer resources used can be accessible over a network. The computer executable instructions may be, for example, binaries, intermediate format instructions such as assembly language, firmware, or source code. Examples of computer-readable media that may be used to store instructions, information used, and/or information created during methods according to described examples include magnetic or optical disks, flash memory, USB devices provided with non-volatile memory, networked storage devices, and so on. 
     Devices implementing methods according to these disclosures can comprise hardware, firmware and/or software, and can take any of a variety of form factors. Some examples of such form factors include general purpose computing devices such as servers, rack mount devices, desktop computers, laptop computers, and so on, or general purpose mobile computing devices, such as tablet computers, smart phones, personal digital assistants, wearable devices, and so on. Functionality described herein also can be embodied in peripherals or add-in cards. Such functionality can also be implemented on a circuit board among different chips or different processes executing in a single device, by way of further example. 
     The instructions, media for conveying such instructions, computing resources for executing them, and other structures for supporting such computing resources are means for providing the functions described in these disclosures. 
     Although a variety of examples and other information was used to explain aspects within the scope of the appended claims, no limitation of the claims should be implied based on particular features or arrangements in such examples, as one of ordinary skill would be able to use these examples to derive a wide variety of implementations. Further and although some subject matter may have been described in language specific to examples of structural features and/or method steps, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to these described features or acts. For example, such functionality can be distributed differently or performed in components other than those identified herein. Rather, the described features and steps are disclosed as examples of components of systems and methods within the scope of the appended claims. 
     Claim language reciting “at least one of” a set indicates that one member of the set or multiple members of the set satisfy the claim. For example, claim language reciting “at least one of A and B” means A, B, or A and B.