It's been understood for some time that mobile operators need to upgrade their base station backhaul links in order to cope with the growing traffic demands of 3.5G data services being driven by dongles and smartphones. That's no less true today as more smartphones hit the market and devices like the iPad promise to kick mobile IP traffic growth rates into high gear.
Which is saying something, considering the current statistics. In Hong Kong alone - where cellcos are already offering HSPA+ connectivity - the average 3.5G consumer is generating 150MB a month, compared to 11MB in 2007, according to Frost & Sullivan. In the US, where the iPhone and Android are fighting for domination, it's around 275MB a month. And that's only going to increase as smartphones become cheaper and more popular, HSPA chipsets are embedded into laptops and consumer electronics, and LTE starts going live.
That's why industry analysts are projecting a serious increase in backhaul capex spending over the next four years. In-Stat expects total expenditures for mobile backhaul - including line leasing, new equipment and spectrum acquisitions - will reach almost $117 billion by 2014, a 41% increase over the $83 billion spent on backhaul in 2009.
However, cellcos in Asia planning their next-gen backhaul need to take numerous factors into account, and not just the inevitable future migration to LTE. Other significant factors include support for legacy TDM services and the possibility of offering wholesale backhaul services to competitors.
Certainly LTE itself is a backhaul design challenge in itself, as the network morphs to a flatter IP/Ethernet architecture and core functions become more decentralized and move to the network edge, with latency for real-time services like VoIP and video an increasingly important metric.
One key challenge that LTE will bring is the sheer number of cell sites that will be required, says Ashley Halford, regional solutions sales manager with Tellabs Asia Pacific.
"LTE cells will be smaller, which is going to have a significant impact on the way operators plan their mobile backhaul networks," he says. "Clearly, with the proliferation of small cell sites, this is going to involve a greater level of distribution of the mobile backhaul network and increase the level of diversity in the connection types, including DSL, microwave and wireless."