New opportunities for cable companies: the MVNO route

Cable companies have had an increasing interest in tapping new market opportunities, as consumption of voice and data sees unprecedented growth.

For most cable providers, going from triple play to multi-play is the logical move on customer demand, so the MVNO route naturally seems the next step.

New needs and use patterns on subscribers’ end make the integration of home and mobile services anytime and anywhere necessary. But as cable operators opt to provide WiFi hotspots to their customers, they also need to offer mobility options if they want to turn them into dependable subscribers.

That’s why it goes without saying that rolling out small, private WiFi networks is not enough for most cable operators. If they want to stay in the competition and provide a mix of media services, voice, and data, they need access to the mobile network capabilities by associating with an MNO.


Partnering not only between a cable company and a mobile network operator, but also between cable providers, is becoming more and more common. On their side, cable companies rally up to ensure they secure themselves a share of the market.

Major players on the US cable providers market, for example, part of the CableWiFi alliance, were estimating the deployment, early 2015, of as many as 10 million new WiFi hotspots around the country, in both homes and businesses. Dual-SSID access points in subscribers’ homes allow the provision of a separate signal for outsiders, who can use that home hotspot without slowing down the network or being granted access to the subscriber’ home network. All the members of the CableWiFi alliance allow their subscribers to use each others hotspots, so, between the five, this could act as a self-reliant WIFI network that uses cellular networks to fill in the ‘gaps’.

Major benefits are evident; cable operators will acquire more customers for their new offerings, while subscribers will gain from getting all their services in one place with reduced subscription costs. But the success of this model still depends highly on cable companies getting to partner with MNOs, who have the necessary network resources to make this model work.

As for mobile network operators, more connected subscribers equals more revenue, which for now may be more to work with than nothing.

The Case for the Unconnected Billions

Sending text messages, going on hour-long calls, or live-streaming videos are such an integral part of our lives that most of us take them for granted. And yet around 3 billion people live, today, in areas without access to basic infrastructure – be it remote islands in the Pacific, developing extra-urban areas, or isolated rural areas everywhere around the world.

Mobile communication can connect these people with one another and with technologies that can prove to be vital. Mobile data enables job seeking in wider area ranges, instantly accessing health care information in case of emergency or risk, or keeping farmers in line with market prices and trends.

In remote, unconnected markets, bringing voice and data coverage can be best achieved using GPRS, which provides wider coverage than 3G, and is easier to adapt to rural, remote, or low density areas. In such places, traditional cellular networks have the disadvantage of being economically counterproductive to deploy, and operators are unlikely to invest in hefty infrastructures that generate relatively little revenue from usage compared to the networks’ lifespan maintenance costs.

The YateBTS technology addresses these issues differently than most other approaches to mobile networks. 2.5G networks using SatSite and YateUCN are a simplified, flexible, and low-cost solution that can be adopted anywhere in the world.

Lightweight, low-power sites

SatSite is smaller than typical base stations which makes it easy to build lightweight cell sites that are especially profitable in higher density networks. SatSite’s low power requirements allow operators to plan self-sustaining mobile networks running on solar or wind energy, avoiding the use of costly power grids or diesel systems.

Bandwidth-efficient backhaul

Unlike traditional networks, a YateBTS/YateUCN mobile network allows bandwidth savings of up to 60%, by using the GTP protocol across the entire network.

bring_cov_2015-6-4_version1.2SatSite acts as a BTS/BSC communicating with the YateUCN core network over GTP, without using any additional network nodes, to simplify the network architecture and minimize the backhaul load. Data sessions in networks using YateBTS SatSite can be established either locally, by assigning the IP directly in the SatSite, or in the YateUCN core network, adapting to the constraints of each location.

SatSite unifies the BTS and the BSC from traditional radio access networks architecture, to eliminate the Abis radio interface used to direct traffic between the BTS and the BSC. In conventional cellular networks, the BSC handling all the communication between the core network and the devices leads to high costs and a substantial load on the network. SatSite base station can communicate with YateUCN over satellite, using GTP to replace the signalling interfaces normally used inside the radio access network and to/from the core network.

A satellite backhaul architecture is adapted particularly to sparse networks in areas with a low density populations, where cell sites are far from the core network; satellite allows operators to serve any location, and improve bandwidth performance for both voice and data services. Combined with the light design and an autonomous operation of the SatSite base station, backhaul over satellite makes YateBTS/YateUCN networks ideal for extending connectivity to uncovered areas.

YateBTS in the age of IoT

These days, everybody’s talking about the Internet of Things. And it’s no surprise that everybody loves it; from operators, who see a chance to attack new markets and better retain customers, to urban consumers who can connect a whole range of devices to an app on their smartphones, and farmers who can use technology to optimize their activities and maximize production.

Bringing IoT to such different audiences while maintaining a high quality of service and an efficient use of network resources is a challenge for most carriers’ current infrastructure capabilities and cost strategies. In fact, a critical concern when it comes to creating IoT infrastructure for new areas is laying the ground for that infrastructure – that is, mobile network coverage.

The number of IoT applications designed for farming and livestock breeding is on the rise, but their actual penetration in rural areas is limited to regions with existing GSM/GPRS infrastructure. Remote and rural areas offer mobile operators enticing prospects not only in terms of IoT coverage, but also in terms of connecting these new customers to their entire range of services such as voice, SMS, or data. But due to the high investment requirements for equipment, civil infrastructure, or maintenance, operators are still reluctant in building mobile networks in there areas.

The success of carriers setting up new networks in remote locations depends greatly on keeping investment and operational costs down, as well as on basing their network equipment choices on redundancy, power efficiency, and flexibility. A reliable IoT infrastructure amounts to operators providing continual service, seamlessly, and in very variable weather and terrain conditions. The geography of each area and the specific needs of communities influence every decision going from civil infrastructure to power supplying and equipment maintenance. In areas with low infrastructure where grid power isn’t available, for instance, carriers must rely on alternative power sources to successfully deploy new networks.


YateBTS-powered IoT applications

A base station like the YateBTS SatSite offers a reliable and flexible solution for carriers to bring mobile coverage to remote rural areas. SatSite is a 2.5G low-power, lightweight base station that allows it to be easily installed anywhere from hill tops to outlying crop fields. Practical for lightweight cell sites, it can be operated in single or three-sector sites using a single solar panel. This generates a substantial reduction in operators’ initial investment costs but also in operating cell sites in the long-run.

SatSite’s low operating costs make it a particularly suitable solution for small farms and rural households, where resources are more scarce and used less efficiently. Access to IoT applications can support these communities in rendering farming activities more productive and sustainable. The flexibility of SatSite’s architecture suits the requirements of specific IoT solutions. Used for any range of applications and devices, from water pumps and soil measurement sensors, to herd tracking and monitoring, SatSite optimizes resource allocation to allow carriers to efficiently adapt their networks to the specific demands of each location.

In rural areas, access to IoT infrastructure can make it possible to attain better farming results, optimize productivity, and increase the overall quality of life. Basic mobile services can create new standards for health care, education, as well as social and economic development of these areas. Operators can play the leading role in this process, provided that their decisions successfully combine cost effectiveness for themselves, and service quality for consumers.

Self-Organizing Unified 2G/4G Networks

The IWPC workshop on self-organizing networks is in two weeks and we are excited about participating. Most of the people there will be talking about self-organizing networks for 4G LTE, which is all good and well, but we are also working hard on SON for 2G GSM networks. Why fit a new idea like SON on an older technology like GSM? Because there are still places in the world that need basic 2G service and a lot of those places don’t have access to any technical staff.

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!”

YateBTS and YateUCN™ make a perfect match for SDMN

YateBTS and YateUCN can be used together to build complete software-defined mobile networks.

YateBTS is a software implementation of the GSM/GPRS radio network. It runs on any Linux and uses a generic digital radio board, the Nuand BladeRF. The entire physical layer is implemented in software, which is different from the usual FPGA- or DSP-based radio design.

For the core network there’s YateUCN, the unified core network based on Yate. YateUCN is a Linux application that can run on commodity servers. It implements the functions of 2.5G and 4G core networks and is easy to integrate in existing mobile operator infrastructure. Like YateBTS, YateUCN replaces hardware routers and transcoders with pure software.
Together, YateBTS and YateUCN form complete software-defined mobile networks, networks that are affordable to build and operate, and networks that can support 2.5G, 4G or even both at the same time.
There are several advantages to the YateBTS+YateUCN approach:
  • Upgradable – We can add new features, like EDGE, with software upgrades or even replace 2.5G GSM/GPRS with 4G LTE using the same hardware.
  • Manageable – Because the entire system is Linux, we can monitor and manage every aspect of the software in a flexible way.
  • Affordable – A pure software approach has much lower development costs and relies on commodity computing hardware.
  • Flexible – The hardware is protocol-agnostic and can be reconfigured to support any mix of technologies.
  • Scalable – The capacity of the core network can be increased just by adding more servers.
Compare this to a conventional mobile network, with its hardwired base stations in the field and big iron like the Cisco AR550 or an Ericsson Mobile Switching Center in the core. It’s all single-purpose equipment, expensive or impossible to upgrade, and all based on proprietary software and hardware with big licensing fees, special training and support requirements.

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.

YateBTS 3.0 is Here!

YateBTS 3.0 is here.  We (Legba and SS7Ware) are a little off of our original one-release-per-month schedule, but not by much. The two big new features in YateBTS 3.0 are:

The cooperation with Nuand has been very rewarding; the BladeRF offers a very affordable platform for experimenters and students to work with YateBTS. The YateUCN support, however, represents a fundamental shift in the capabilities of open source mobile networks. YateUCN was designed to provide VoLTE service in a IMS 4G core network, but it also can act as an MSC/VLR for the 2.5G YateBTS. YateUCN can use SS7 protocol to a legacy HLR or talk DIAMETER to a new-generation HSS. This means that YateUCN allows us to integrate YateBTS directly into existing SS7 infrastructure, something that has been a significant roadblock for similar RAN implementations. This capability is not hypothetical; it has been demonstrated using the same  HLR that is used by Yate MVNO customers in production networks. And since YateUCN is an IMS system anyway, it will allows operators to build mixed 2G/4G networks using a combination of YateBTS and standard eNodeBs, what we call a Unified Core Network.

The short of it is that with YateUCN, YateBTS is compatible with nearly all existing and foreseeable mobile operator core networks.  For me, this represents a huge milestone for what started as OpenBTS, a possibility that has existed for a long time but has only now been realized. More importantly, it gives operators the chance to lower costs by using 2G in those places where it is an appropriate choice, even after the shift to IMS core networks. I hope to address the importance of that  capability in a future post. Until then, get a Lab Kit and have fun playing with YateBTS 3.0.

YateBTS 2.0

By the time you read this, Null Team and Legba will have released YateBTS 2.0. The big new features are authentication and USSD, both of which are important stepping stones for roaming support, and a new web-based interface for network-in-a-PC configuration. (Note that USSD support is in the commercial release only.)

When YateBTS was initially released, just last month, several people commented that the roadmap was very “aggressive”, by which I think they really meant “unrealistic”.  Getting the 2.0 release out on schedule, along with continuous improvements to the documentation, will convince people that the companies are serious about developing and supporting this product.  The speed with which Null are adding new higher-layer features also demonstrates the power of Yate’s Javascript interpreter to simplify the coding of the GSM control layers.

Meanwhile at Legba, we are working on other aspects of YateBTS, like EDGE, for upcoming releases.  More on that soon.

Salut, YateBTS!

Today, we are proud to announce the release of YateBTS 1.0, the result of a collaboration between my new company, Legba, Inc, and the good people at Null Team SRL, the home of Yate.

YateBTS is basically the OpenBTS L1 PHY, L2 link layer and L3 radio resource manager, with all other functions implemented in Yate.  This offers some huge advantages over the original OpenBTS SIP interface, including dramatically improved stability, direct support for the all of the protocols already supported by Yate (XMPP/Jabber/Jingle, H.323, MGCP, IAX, ISDN, and others) and lots of other Yate features, like SNMP.  Most notably, though, when YateBTS is used with the commercial version of Yate, it gets the benefit of Yate’s deployed and certified SS7-MAP interfaces, for ready integration into existing mobile infrastructure, including roaming support.

Architecturally, YateBTS is built from a “decapitated” version of the OpenBTS public release, called “MBTS”, interfaced to Yate over a socket.  Through this socket, the Yate messaging engine sees abstract “connections” that represent the dedicated radio channels to the mobile stations.  This approach allows Yate and the MBTS component to be licensed independently.  So MBTS inherits the OpenBTS AGPLv3 license and Yate is distributed under either GPLv2 or a commercial binary license, depending on the version.

In the first public release, YateBTS supports GSM-FR calls, SMS and GPRS.  This is a smaller feature set than OpenBTS, but since Yate now allows the control layer to be coded in Javascript, we expect new features to develop very quickly.  (Really; once we decided to build YateBTS it only took a few weeks to get this far.)

I hope everyone has fun with this new toy.

That said, YateBTS is not the main thing we are working on.  More on that later. 😉