With the completion of the 3G and broadband wireless access (BWA) spectrum auctions, the sector is gearing up to replicate the success of mobile telephony in broadband. The potential of BWA technologies is evident from the fact that the auctions fetched the government over seven times the reserve price per block. tele.net recently organised a conference, “BWA in India”, to provide a platform to discuss the potential and challenges associated with these services. The following section on Impact on Infrastructure Requirements brings forward the views of Sharat Chandra, President and COO, Strategy and New Technologies, GTL Limited….

There has been an exponential rise in the demand for data globally. According to statistics released by the Cisco Visual Networking Index, global mobile data traffic will witness a 39-fold increase, or a compound annual growth rate (CAGR) of 108 per cent, between 2009 and 2014. In the Indian context, mobile data traffic will witness a CAGR of 222 per cent during the same period.

To accommodate this shift from voice to data, broadband wireless access (BWA) networks will need to be planned and dimensioned accordingly. Also, internet protocol (IP)-based skill sets and tools will be required to plan and operate data networks. This raises the question: how much of the existing voice-centric network resources can be shared for data networks?

There are several myths surrounding the implementation of BWA networks. For instance, it is widely believed that BWA rollout will merely entail an overlay to 2G and 2.5G network infrastructure. This does not hold true since KPIs such as jitter, latency and throughput are not the same as in a voice network. Another commonly held notion is that BWA rollout would be a plug-and-play concept since substantial passive infrastructure already exists. This too is false, as the existing antenna ports, cables and energy are already being used to expand legacy and 3G networks. Also, detailed radio planning is a must for rolling out BWA networks, as BWA equipment cannot just be installed on the existing towers.

Similarly, the existing backhaul cannot be upgraded to accommodate BWA traffic for several reasons. First, BWA networks are expected to deliver 100 Mbps of throughput at the access layer. To support this, an equally broad pipe will be required at the backhaul level. Therefore, a thorough audit of backhaul availability needs to be undertaken and new solutions such as Ethernet or hybrid radios will have to be explored and implemented.

The infrastructure requirements of BWA networks are altogether unique. To roll out such a network, more base stations per cluster are required. This is because fewer subscribers can be served per site. To illustrate, around 400-500 users per base transceiver station (BTS) can be accommodated on BWA networks versus 2,000+ users per BTS in GSM networks. Also, increased path loss on BWA is witnessed due to a higher frequency of operation than on 2.5G networks, and more micro/pico/femto cell sites are required for in-building coverage. Of course, the shareability assessment of each tower is essential for gauging if it can accommodate a BWA tenant.

The ideal requirement for a 4G backhaul network includes adequate capacity, latency, a sound IP base and adequate quality of services. However, a few challenges with regard to the backhaul are evident. For example, existing wireless backhaul networks will not be adequate to cater to BWA data traffic. The transmission network for BWA will require either IP radios or hybrid radio systems that support gigabit rates of data transfer. A solution may be to utilise dark fibre or copper and ink partnerships with utilities.

While the demands on the access network can be met with current advanced BWA technologies, the real challenge lies in setting up the distribution segment, which is the backhaul network. How does one create additional bandwidth on the existing legacy backhaul networks? Typically, operators have deployed a combination of ring, mesh and spur architecture. While some of the segments may have capacity left to accommodate additional bandwidth, many of them may not.

Recent advancements in mobile wireless technology indicate the availability of radios that can support gigabit data rates. However, spectrum in short distance MW bands such as 15 GHz, 18 GHz and 23 GHz are getting exhausted and new bands need to be explored. For example, for dense urban areas where the inter-site distance is less than 250 metres, gigabit radios in the 70 GHz band can be considered. This, however, needs to be taken up with the regulator for opening up new bands.

Similarly, hybrid radio systems that can provide better throughputs and yet support the native TDM for the ongoing traffic need to be examined as upgrade solutions for wireless backhaul of next-generation BWA networks.

Moreover, a multi-vendor and technology environment poses numerous challenges. The equipment and services for multi-network topologies such as 2G, 3G and BWA are  diverse and require different skill sets and tools. To meet these requirements, one can consider shifting towards unified operations, deploying a centralised management system, integrating all network equipment into a single-window solution, integrating operation support systems (OSS) and business support systems (BSS) and efficiently managing space, power and infrastructure assets.

Integration of different kinds of network equipment into a single network management system provides better control and end-to-end visibility of not only the network’s performance but its impact on services such as health and customer experience. It enables a proactive response leading to reduced customer complaints. Similarly, the integration of OSS and BSS on a common platform across multiple network topologies of the operator paves the way for centralised customer relationship management, call centre and billing for a variety of services including voice, video and data. Space, power and asset management by infrastructure providers reduces the complexities of sharing common network resources by implementing a geographic information system for remote maintenance, site feasibility checks, inventory allocations, etc.