By Frank Rayal
Cisco’s intent to acquire small cell vendor Ubiquisys is yet another demonstration of the changing landscape of mobile communications and services. But the question is to what extent such an acquisition would provide Cisco with a much coveted play in the radio access network?
Cisco has long played in WiFi, a technology that has surpassed its initial objective to provide local area networking to become a complementary service used by mobile network operators to relief congested sites and inject capacity in targeted spots. As WiFi gets more integrated into the mobile network architecture with seamless handover, authentication and a host of other features that blurs the boundaries with licensed spectrum technologies such as HSPA and LTE, Cisco’s role will continue to grow, especially as it has a strong core network portfolio.
The acquisition of Ubiquisys expands the field for Cisco to play in a complementary (or in other instances, a competitive) space – that of licensed band small cells. These small cells come in different shapes and forms: indoor residential, indoor enterprise, indoor or outdoor public are but a few distinctions. The bulk of current sales and deployments are for the femto category deployed in the home.
Many operators made use of femto cells to provide indoor coverage where it is weak. But with mobile traffic generated indoors reaching 65% or more, the case has always been for small cells to take a good portion of that traffic off the macro cellular grid: the projected volume of femto cells according to Informa1 will get close to the 90 million mark by 2016.
Herein lies the challenge: to what extent are vendors willing to collaborate on interoperability to enable a seamless radio access network?
To accommodate the deployment of large numbers of home base stations, a gateway is used to control and manage these devices, thereby enabling the operator to scale small cell deployments. This creates a demarcation line between the small cell network and the macrocell layer. To date, the integration of small cell technology with the macro cell layer, from a radio interface perspective, has been limited. In fact, one of the features of Ubiquisys solution is the ability to accommodate to some extent the presence of the overlaying macrocells, reducing interference in the process to everyone’s benefit.
But as radio access technologies evolve, particularly LTE, the small cell layer will get more integrated into the overall network to enhance performance. The small cells and macro cells can coordinate their transmissions to avoid interference. This coordination requires tight integration between the different cell layers, something that the LTE standard allows for by implementing the X2 interface which enables communication between base stations. However, LTE does not specify how a base station should respond to a message from another base station, leaving the question open for vendors to work it out among themselves.
Herein lies the challenge: to what extent are vendors willing to collaborate on interoperability to enable a seamless radio access network? And, to what extent are operators willing to mix base stations from multiple vendors in the same market? The case is highly pertinent for outdoor small cells which are more prone to interference than indoor femto cells. What is interesting about this acquisition is that Cisco, a core network player, is extending its reach into the radio access through an indoor application. It remains to be seen whether the jump can be made to the wider radio access space.
Frank Rayal is co-founder of Telesystem Innovations a boutique management and technology advisory firm specialized in wireless communications. He advises investment firms, vendors, and operators on technology strategy, spectrum, and business and market analytics.