SS7ware’s insights from the MVNOs World Congress

VNOs World Congress 2017 (1)

We just got back from the MVNOs World Congress, in Nice, where we did quite a good impression with our YateHSS/HLR and YateUCN solutions for MVNOs. The “not so shocking” conclusion that we came to was that our public pricing policy impacts the MVNO market at its core.

We already knew that, so the real benefit of the conference for us was that we got closer to the needs of our customers by talking to them about their troubles as MVNOs, MNOs and IoT MVNOs.

We share the knowledge, so here are some of the insights:

1. MVNOs need our network equipment (YateUCN as a GMSC, GGSN, PGW and YateHSS/HLR) because of the flexibility given by the features included in the Yate software and the use of off-the-shelf hardware.

In the case of the YateUCN (unified core network) the Yate software implements the functionalities of 2G/3G/4G core networks in a single server. We made it that flexible in order to ease the businesses of MVNOs and MNOs as well. YateUCN works for MNOs as MSC/VLR, SGSN, SGW.

2. full MVNOs choose our products because their businesses aren’t sustainable on the long run with big vendors’ products (such as Cisco, Huawei) that ask 4 times the costs of an YateHSS/HLR for an upgrade.

As the network grows, the CAPEX and OPEX expenditures/subscriber decreases significantly with our MVNO solutions. We charge per license and once your network grows in number of subscribers, you just add another server in a cluster. The YateUCN and YateHSS/HLR solutions are scalable, redundant and load-balanced due to the clustering module implemented in the Yate software.

3. the IoT MVNOs use our GGSN/ PGW solution (YateUCN) to offer mobility to the IoT devices and a positive return on investment for the MVNO business, within 6 months or less.
SS7ware’s full IoT MVNO network solution consists of two products, YateUCN and YateHSS/HLR, both with license costs at $31050, which is about $0.62/ device for a network of 100.000 devices.

4. the strategy of MNOs is to officially sustain MVNOs businesses, because MVNOs play well on the segmented markets and by doing this, they take market shares from competition.

Please feel free to send us questions at or visit our website,, to learn more about SS7ware’s MVNO solutions.

Hope to see you in November at the MVNO Conference in London.

SS7ware Inc.

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YateUCN, the EPC cloud

The YateUCN is an LTE EPC that unifies all the functions of a conventional LTE core network into a single server. A single YateUCN unit combines the MME, SGW, PGW, PCEF and PCRF functions. A pool of YateUCN servers provide seamless horizontal redundancy, scalability and load balancing in the LTE core network. The YateUCN also replaces the latest core network approaches to design and management, such as network function virtualization (NFV) that virtualizes the functions of the network’s nodes in software or software-defined networking (SDN) that splits the control plane from the user plane.

A conventional LTE core network has many components and each requires a back-up node for redundancy. To ensure load balancing, operators need to deploy load balancers and external servers, which only add to the complexity count.

The YateUCN servers that form the EPC cloud have a many-to-many relationship with the eNodeBs, are equal at application lever, and eliminate the single point of failure between the RAN and the core network. All these characteristics allow for horizontal redundancy, load balancing, easy management and an overall simplicity within the network.


Redundant EPC

In conventional LTE networks, all core network components (MME, SGW, PGW, PCEF, PCRF) need to be duplicated to ensure redundancy and synchronization in case of failure. With a YateUCN-based core network, operators add extra servers to the existing pool to increase the network’s overall capacity.

To achieve redundancy, subscribers get assigned to random servers from the YateUCN pool. If a YateUCN fails, all the devices served by that unit are automatically re-assigned to other available YateUCN servers, as seen in the diagram.yucn_redund_epc_2015-11-18_version1.3

LTE core network cloud

A cluster of YateUCN servers act as an LTE core network cloud, providing all the EPC services: mobility, authentication, quality of service, routing upload and download IP packets, IP address allocation and more. Mobile operators eliminate the occurrence of a single point of failure between the RAN and the core network because YateUCN servers are equal at application level, and have a many-to-many relationship with the eNodeBs.

By removing the single point of failure possibility, mobile carriers can build scalable and considerably leaner core networks, while also providing load balancing for enhanced flexibility.

Each YateUCN core network server is implemented in off-the-shelf servers commodity software (Linux), offering a shorter lead time, more servicing options and faster replacement time.

Integration in existing LTE networks

The entire LTE EPC layer is implemented in a single YateUCN unit, meaning that it replaces the MME, the SGW, the PGW, the PCEF and the PCRF units of conventional networks.

The YateUCN is compatible with any generic LTE RAN and core network component. It supports the S1-AP and GTP interfaces between its MME and SGW functions and the eNodeBs. The YateUCN uses Diameter (S6a) to connect to an existing generic Home Subscriber Server (HSS). The unified server can connect to external PGW and SGW via the S5/S8 interface. To link to an existing IMS, to the Internet or to an MMS service, the YateUCN uses the SGi interface. Finally, to interrogate an external Equipment Identity Register (EIR) about blacklisted IMEIs, the YateUCN uses S13 over Diameter.

Additionally, the YateUCN also implements the IMS functions necessary for deploying VoLTE, but this will be detailed in a future article. In the meantime, previous blog posts have detailed the YateUCN’s VoLTE call with an iPhone 6 or how the YateUCN handles SRVCC.

A few final words

A unified core network server that delivers redundancy, scalability, load balancing and flexibility allows mobile operators to tap new core network equipment innovations and reduce their CAPEX. Easily integrated in an existing LTE network, the YateUCN makes it possible for mobile carriers to optimize their networks and replace solutions typically characteristic to the recent mobile LTE deployments, such as NFV or SDN.

SDN and beyond

Software-defined networking (SDN) and network function virtualization (NFV) are new approaches to designing and operating mobile networks, granting operators better management possibilities and better use of the network capabilities.

NFV represents the virtualization of network nodes roles, which culminates in separate software implementations performing the functions typically executed by hardware components. At the other end, SDN uses the virtualisation technology to split the control plane (where you need flexibility) from the data plane (where you need speed/performance). However, the price for this is complexity which translates into high operation costs.

Operators benefit from such frameworks because they increase the network capacity and performance, and allow for better manageability.

The YateUCN approach recognizes the usefulness of separating the user plane and the data plane, but it implements both of them in software. The control plane is implemented in the user space for flexibility while the user plane in the kernel space for speed.

As a result, operators who deploy YateUCN networks will gain from considerably scaling down equipment, and will have better control over the network scalability and performance requirements. The image below shows the YateUCN implementation and a common SDN deployment using an OpenFlow switch.

Unified Core Network vs. Common SDN deployment

Common NFV/SDN implementations rely on virtualizing the EPC, so that the functions of the MME (Mobility Management Entity), the SGW (Serving Gateway), and the PGW (Packet Data Network Gateway) are each implemented in software and run on the same hardware. Drawbacks of this approach include:

  • the separation between the control and user plane is achieved by means of a switch, usually hardware-based and external to the network. This is a limitation of software-defined network functions;
  • the switch is designed to replace the PGW and obtain the IP connection which it sends to the eNodeB over the user plane. This means that it must support both GTP protocol for the user plane and IP which determines the high costs for such equipment.
  • the complexity of NFV requires additional effort from the network to accommodate it, which increases the overall cost of the solution.

The implementation of YateUCN differs significantly from the above.

First, it uses commodity hardware, so no special-purpose equipment needs is needed. Simply put, YateUCN is a COTS server, which completely diminishes investment, staff, space, and power requirements.

Secondly, YateUCN differs from virtualized EPC because it implements a unique software, based on Yate, that performs all functions of the MME, SGW, and PGW. All-software implementation also means that multiple protocols (Diameter, SS7) are equally implemented in YateUCN, and no additional implementations are required for the core to connect to the Home Subscriber Server or IMS. This helps operators cut down on highly specialized staff needs and facilitates inter-working with legacy networks.

Thirdly, instead of using a hardware switch, YateUCN implements it in the Yate kernel. Because the Unified Core Network is based on Yate, an expandable Linux-based telephony engine, it was possible to integrate a software switch in the core software, allowing for much faster data processing and eliminating the need to work with multiple vendors.

YateUCN core network solution removes the barriers of entering the market due to simplicity, scalability and low cost. YateUCN specifications features and specifications list can be accessed here.

Unified Core Network Demo with iPhone 6

Recently, we verified the interoperability of the new iPhone 6 with the Unified Core NetworkTM, by performing the industry’s first VoLTE call from a GSM mobile phone to iPhone 6, through a single unified switch. This is a Big Deal. Why?

First, Some Background on the Problem

One of the changes 4G LTE is forcing on mobile operators is the elimination of older SS7 MAP core networks of 2G and 3G in favor of IMS. However, many critical services, like roaming are not yet “fully baked” in IMS, so operators will probably continue to run 2G and 3G networks for the foreseeable future. In fact, mixed 2G/4G deployments are happening in many places right now and those operators are in the situation of installing and managing two nearly independent core networks.

The Solution

SS7Ware’s Unified Core Network (UCN), along with YateBTS is the answer to the 2G/4G mixed network problem. The UCN provides a “packet core” for routing internet traffic and an IMS/VoLTE core for handling calls and text messages. It works with YateBTS to support 2.5G GSM/GPRS handsets and with any standard eNodeB to support 4G LTE devices . We first introduced it with this video. (In that first video we referred to “OpenSAE” and “OpenVoLTE” as two different things, but we have since combined them into a single UCN server.)

Unified Core Network The switching, routing and mobility management functions of the core network (4G SAE/IMS and 2G Mobile Switching Center/Visitor Location Register/GPRS support node) are implemented in a single UCN server. This approach offers many advantages:

  • Simplified architecture; even a large network is just many copies of an identical box.
  • Simple scalability; just add more servers.
  • Increased network resiliency: there is a many-to-many relationship between radio sites and UCN servers, with seamless failover and load balancing.

And now the Demos!

Most recently, we have been testing the UCN with the IMS client in the new iPhone 6. (Unlike  over-the-top applications like Skype, a true IMS client is implemented in the baseband processor, so using a true VoLTE-capable handset is critical.) We used the UCN with an an off-the-shelf LTE eNodeB to provide a 4G radio network for the iPhone and we used YateBTS to provide a 2G radio network for a second test phone. In this first demo video, the iPhone registers to the UCN through the 4G radio network and the GSM phone registers to the UCN through the 2G radio network.

The two phones register to the same HLR using SS7-MAP. Then, we exchanged text messages between the two handsets. If you are a hardcore techie, here is a ladder diagram: 2g_4g_register_sms_sip_map-video And here is the signaling trace from the UCN server console. If you look at the ladder diagram, you see that we are using conventional SS7-MAP to register an LTE iPhone6 to the HLR. This solves the LTE roaming problem, and we can do it thanks to the Yate messaging engine, which is the basis of the UCN server.

In the second demo video, we make phone calls between the two handsets.

For the 2G phone, this is an ordinary circuit-switched GSM call. For the 4G phone, this is a VoLTE call. What is special here is that these calls are being handled by a single switch in the UCN, behaving as a 4G IMS and a 2G MSC at the same time. We can do this because the UCN server is built on Yate, which combines one of the most solid SIP implementations in the industry with carrier-certified SS7-MAP support, and because YateBTS gives us a very LTE-like RAN for 2.5G.

We have already had the opportunity to present this technology to mobile operators. Their first reaction is disbelief, followed by a lot of excitement. “You mean we can use CAMEL on a VoLTE call?”  “You mean we can authenticate 4G handsets in an ordinary HLR?” “You mean we can run GSM and LTE out of the same core network?” And to this we say, “Yes, you can!”

Revolutionary Features in YateBTS 4

YateBTS 4 introduces redundancy support for YateUCN. This is a revolutionary feature that deserves some explanation.
Redundancy failover and load balancing.
A YateBTS network is a many-to-many mapping between YateBTS base stations and YateUCN core network servers. Core network loads are distributed evenly and are redistributed automatically if a server fails. The resulting network is resilient and easy to manage. To add more capacity, just add more servers. If a server fails, its users are shifted to other units within a few seconds. This is a sharp contrast to the conventional mobile network, a hand-configured, tree-like hierarchy, with points of failure that become more concentrated as you move toward the HLR.
Release 4 also introduces handover support, which is revolutionary in its own way because it is done very differently from conventional GSM. Because YateBTS has no BSCs, handover is a peer-to-peer operation. The result is a 2.5G radio network that behaves much more like LTE, which is one of the innovations that make the Unified Core Network possible.
 handover_scheme_2.2Handover support is done using SIP
YateBTS Release 4 has been available since July, but got little fanfare at the time. That won’t be the case with Release 5, which will be ready soon, so watch this space.