The use of Mobile Virtual Network Operators is a concept until recently not commonly known by nonspecialists, and even MVNO customers may potentially be unaware of who is providing the service and with what technology. From a customer point of view, there is no difference between the services provided by an MVNO versus a traditional wireless carrier, while in reality the services are provided via some form of agreement between the MVNO and the actual cellular networks operator. With the advent of alternate wireless access network providers, such as WLAN Internet service providers, or WISPs, MVNOs may also offer service via a variety of access media. In addition, there may be different flavors of MVNO depending on its level of engagement in the physical network operations. Lightweight MVNO differentiates based on unique customer care and branding, while full-scale MVNO not only focuses on branding but also operates some critical network elements.
A lightweight MVNO focuses its activity on mobile customer acquisition and retention, marketing campaigns, customer care, and branding. These operators do not want to enter into the technical aspects of managing services, and they believe services offered via the network of a partner, or multiple partners, are sufficient to satisfy their customer needs and to prevent them from switching to the competition. Typically, they lease space on existing carrier HLR and AAA servers and use that carrier's infrastructure or roaming agreements. Alternatively, MVNOs might use their own HLRs and AAA servers and simply have roaming agreements in place with all the national carriers with special conditions regulated by their MVNO status.
These operators do not require huge up-front investments, and they can invest all their efforts in subscribers' growth and satisfaction, and can leverage their branding power by letting existing players bid for their business. One example of an existing Voice MVNO is Virgin Mobile in the United Kingdom and the United States, where the strong Virgin brand and distribution infrastructure allowed it to sign up millions of subscribers in a relatively short time period. The MVNOs may also define their own applications partners in order to further differentiate themselves from the competition and the services provided by a wireless carrier whose infrastructure they are using. The MVNOs are normally expected to operate in the consumer market space, although they may later branch out to serve small businesses.
A full-scale MVNO adds value to the plain access network connectivity offered by incumbent operators by operating some elements in the core network. In a 3GPP-defined system, for instance, the MVNO may want to operate the HLR, the AAA servers, and the GGSN or logical partitions of GGSNs (virtual GGSNs) offered to them by existing wireless carriers for sharing. In 3GPP2-defined systems they may operate parts of the clusters of Home Agents, PDSN, and AAA servers. Full-scale MVNOs may operate applications jointly with existing ASPs and use these and other similar relationships to address the corporate market via managed VPN services and corporate data services applications. A traditional wireline carrier serving significant numbers of business customers may decide to add wireless access support for them to extend its product line and act as MVNO, thus retaining customers' ownership. This class of MVNOs is willing to compete for technical elements of service delivery, either because they believe their experience gives them a competitive advantage or because they know how to handle the existing customer base and they believe it is in their own best interest not to lose it to competitive offers from wireless carriers.
It is clear that the existence of MVNOs needs to be taken into account when MVPN's technical solutions are defined, since the MVNO itself may be a special kind of wireless carrier customer. As mentioned, the MVNO sometimes does not want to engage in network operations, and the wireless carrier therefore offers complete outsourcing of network operations for them. In such lightweight MVNO cases, the MVPN technical solutions do not change much.
The MVNO may ask the wireless carrier to offer an MVPN service over which the MVNO implements a captive portal (see Chapter 5) where their subscribers are being authenticated and where they select the services they want to subscribe to or want to use during a particular session. This VPN may provide the access to multiple areas associated with bundles of such services. The MVNO may ask the wireless carrier to construct other additional VPNs to support application-specific networks that only subscribers to these applications have the right to access. Additionally, if the lightweight MVNO had to support corporate networks, they would ask the partner to entirely manage the technical aspects of the SLA and service integration, perhaps together with a third-party technical partner who may have a relationship with a number of enterprise customers the MVNO could leverage.
Alternatively, the MVNO could lease GGSNs or virtual GGSNs (or HAs in the 3GPP2 systems) from the wireless carrier and manage them according to the rules set forth in the contract defining this business relationship. It also may fully manage the integration services and corporate customer support. In this case, the ownership of the gateway node implies that the MVNO may freely manage the VPNS they offer to their customers, and the MVNO must also operate the DNS server necessary for networks to resolve the APNs to IP addresses on the GGSNs it operates.
In yet another scenario, the MVNO might offer voluntary MVPN services based on the IPSec or Mobile IP VPN client to their customers, to provide for the support of multiple access technologies and to terminate the IPSec connection at a VPN gateway or HA residing in the MVNO data center (or let the customers themselves own or lease the CPE equipment), before delivering traffic to the appropriate customer network. This scenario makes use of platforms specialized to handle a large number of IPSec tunnels and to support virtual VPN GW service so that each customer network is assigned a virtual VPN GW, or to apply switching between ingress and egress virtual interface based on the customer network identity and not based on IP routing. However, we do not believe this will be a mainstream scenario because of heterogeneous requirements from corporations and the potential overhead of the air interface, especially when used with legacy air interface technologies such as GSM.