Full MVNO Architecture - MVNO Core Network

What is a full MVNO?

A full MVNO is a mobile operator that provides services to its subscribers without owning a Radio Access Network. 

A full MVNO will need his own HSS/HLR, GMSC, GGSN, PGW and SMSC. Depending on the business model you choose to apply there are other Core Network nodes that you could use, such as USGW or OTA gateway.

Full MVNO Architecture

The MVNO architecture would look like the following diagrams and it would be the Home Network. It will use the RAN and a part of the Core of the MNO that it has a roaming agreement with.

The MVNO network is called Home Network while the MNO network is called Visited Network. These two communicate with each other based on a roaming agreement. 

The Roaming agreement is the business understanding between the two operators that settles the ground base on which they will collaborate. It is a signed contract that sets the rules on which they are going to work together. 

The Home Network and the Visited Network communicate with each other via the Anchor nodes. 

ServicesGSM (2G)LTE (4G)
SignalingVLRMME
VoiceMSCVoLTE technology
DataSGSNSGW
  • STP (Signal Transfer Point)
    The SS7 messages are routed through STP (Signaling Transfer Point) in GSM using SS7 (VLR) protocols.
  • DRA (Diameter Routing Agent)
    For LTE the messages are routed through DRA (Diameter Routing Agent) using Diameter.

1. Mobile-terminated (MT) calls in MVNO network

We’ll start with the easy part of voice calls, which are MT (Mobile Terminated) calls. They are standard and do not pose any technical issues for an MVNO.

  • 1.
    PSTN to GMSC
    The call arrives in the MVNO network from the PSTN and goes to the GMSC.
  • 2.
    GMSC to HLR
    The GMSC sends a Routing Request to the HLR. The HLR checks to see which MSC the subscriber is registered.
  • 3.
    HLR to MSC
    The HLR verifies the subscriber and requests the Roaming number from MSC.
  • 4.
    MSC to HLR to GMSC
    This MSC is sending the HLR the response to its request and the HLR sends to GMSC the roaming number.
  • 5.
    GMSC to MSC
    The GMSC is sending the call to the MSC of the subscriber.
  • 6.
    MSC to RAN and MS
    The MSC is sending the call to the Radio Access Network and then to the Mobile Station.

2. Mobile-originated (MO) calls

Usually, the Home network doesn’t have control over the call because it doesn’t go through the MVNO architecture. This would make the billing enforcement very difficult. You would not have any information on the subscriber’s activity or when he reaches his limit. Therefore, technical MVNO solutions were created in order to solve these problems, such as SCF or MO Gateway.

The HSS/HLR of the MVNO provides extra information to the visited network (MNO). The MSC of the visited network makes a CAMEL request to a node called Service Control Function (SCF) whenever a call is made. This Service Control Function performs third-party call control over the call and can disconnect it when necessary.

The MVNO can also divert the call from the visited (MNO) network’s anchor node to a Mobile-Originated Gateway that belongs to the home network (MVNO). This way the call can be managed in whatever way the MVNO decides. The call is sent to the target network and can go on a special route with lower prices. These kinds of MVNO solutions are often used to provide cheaper routes that would support your business model.

3. Short Message Service (SMS)

A full MVNO needs to interconnect with all the national operators and with a roaming hub for Short Message Services.

Number portability is one of the reasons why an MVNO has to interconnect with all the national operators. If a subscriber is porting his number to another network you have to send and receive calls and SMSs.

 To deliver a short message from a subscriber, the message has to go through the SMSC of the visited network (MNO) first and then to the SMSC of the home network (MVNO) based on information written on the SIM.

 The SMSC stores the message and interrogates the HLR about the target address of the message. It will receive an answer and try to do a delivery according to the answer.

 If the receiver of the message is a subscriber of another network, the home SMSC will send the message to the target network’s SMSC.
 It is very important for any operator to send and receive SMSs of its subscribers and that’s why it’s mandatory to interconnect the SMSC

Yate-based MVNO architecture

  • YateUCN

    ✔ A unified GSM and LTE Core Network that implements in software the functions of GMSC, GGSN and PGW
    ✔ YateUCN uses the HLR to localize the MSC/VLR of the called subscriber and routes the call to the designated MSC/VLR in the MNO network.
    ✔ It establishes and maintains the IP sessions of the subscriber and routes the IP packets to the SGSN in the MNO network.
  • YateHSS

    ✔ A software implemented product that provides the functionalities of LTE HSS and GSM HLR.
    ✔ You can use this product for both Circuit-switching and Packet-switching, so your subscribers can roam from a 4G network to a 2G/3G network and back.
  • YateSMSC

    ✔ A SMSC with the functions of receiving, forwarding, storing and delivering SMSs in GSM, UMTS, LTE or custom networks.
    ✔ Uses standard SS7/MAP and SMPP interfaces.
    ✔ USSD services are included in YateSMSC.
YateBTS core network MVNO solutions

Test your network before deployment

A full MVNO architecture needs to be tested for every technical aspect. For every service package there are multiple scenarios that need to be tested.

You need to know ahead how your equipment will work and how you can build up your network. 

  • The service package
    ✔ Calls - the duration and number of calls
    ✔ SMSs
    ✔ Data Sessions
  • SIM registration
    ✔ Test the SIM cards you purchase
  • Roaming
    ✔ How are the services working when roaming
    ✔ The average timeline of authentication when roaming
  • Radio Network
    ✔ Getting experience before entering the tests with the MNO

VoLTE Lab is a complete test suite for Voice-over-LTE, that includes the LTE LabKit, the MiniCore and two iPhone 6s. It is fully configured and intended for use as a VoLTE test bed and learning environment. With VoLTE Lab you can have a deep view into the internals of VoLTE technology, with Wireshark.