Mobile Network Operators are starting to deploy 4G LTE to meet the growing demand for bandwidth as data traffic continues to grow at exponential rates on their wireless networks and will look to upgrade to newer technologies like LTE Advanced over the next few years. Simultaneously they are also looking at new networking architectures to meet the challenges of coverage and capacity – especially in areas of high data traffic such as city downtowns in emerging and developed nations.
Presently, carriers are using Wi-Fi hotspots to offload data traffic on their 3.5G/3.75G networks and are teaming up with Wi-Fi service providers to increase Wi-Fi coverage in city downtowns. With a growing number of smart phones and a significant number of feature phones supporting Wi-Fi, this is proving to be an effective short term solution.
In the longer term, carriers are looking at their radio networking architecture to evolve into heterogeneous architectures to meet anticipated growth in data traffic. In these heterogeneous architectures of the future, small cells or metro cells will used to complement macro and micro base stations to provide enhanced coverage and capacity. Typically these small cells will be mounted on street lights or on the sides of buildings in city downtowns and will provide coverage over 1 city block or 2 city blocks. Small cells will have lower power transceivers and will use microwave or fiber (where available) for back hauling of data into the core network.
However, as the networking architectures will continue to evolve, wireless carriers, infrastructure OEMs and semiconductor supplier are also starting to investigate the next generation of distributed heterogeneous architectures. In these distributed architectures the baseband and radio functionality of the base station will be housed in separate locations. This will allow a centralized baseband in a base station to control multiple radio transceivers that are geographically dispersed and remote from the baseband.
The driving force behind the consideration of this distributed architecture is that the radio capacity can be dynamically matched to demand and this capacity can be transferred from one location to another depending upon needs. During the day, the radio capacity can be allocated to the city downtown and in the evenings, or on weekends, this capacity can be transferred to the suburbia with a reduced number of basebands controlling multiple transceivers.
While Cloud RANs offer the advantage of dynamic capacity management and reduced equipment costs, the architecture offers its own unique challenges. Unlike small cells, in cloud RAN architecture, the data processing is done at base stations, remote from the transceivers. To address issues of low latency, Cloud RANs require high speed fiber optic links between the base station and the transceiver. And since multiple geographically dispersed transceivers are connected to a single base station, Cloud RANs work best when high speed fiber optic links are available in all the sites.
IHS iSuppli expects that carriers will start to investigate Cloud RAN architectures like the Liquid Radio solution from Nokia Siemens Networks and the Light Radio solution from Alcatel Lucent over the next few years. The decision to go with architectures like Cloud RAN will depend upon the spectrum available to the carriers, the frequency range of this spectrum, the availability of optical fiber to connect the remote transceivers to the base station and the topography of the networked region. These solutions will co-exist with small cells and Wi-Fi hot spots and provide another tool for operators to address the challenges of capacity on their networks.
Read More About Mobile Infrastructure > Mobile Data Explosion Driving Transition to Heterogeneous Networking Architectures and Small Cells