The mayor of London (Big Borris) worried out loud about the prospects of UK mobile data networks melting over the load of data expected to hit during the Olympics. And he’s right.
This is a HUGE issue making its way across the globe as cellular networks, initially designed for voice traffic, are faced with having to accommodate monstrous volumes of data traffic.
While macro cellular networks will continue to guarantee wide-area coverage, operators are rushing to find complementary alternatives that help ease the pressure, especially in high-traffic areas.
Wi-Fi offload is widely considered one of the best solutions in areas where 3G/4G subscriber density and usage is high – such as urban areas, and locations like airports or stadiums.
Operators are also exploring additional solutions, such as small cell underlays to address high capacity density, and complement and strengthen their Wi Fi and macro deployments.
Mobile operators can further improve network utilization by actively managing the traffic beyond the RAN within the core, using content caching, tiered pricing, and policy enforcement. While these solutions do not increase capacity, they make data transmission more efficient, letting operators to pack more content within the same infrastructure.
Bucking convention with a different type of decongestant
Convention says to simply increase cellular capacity to boost cell density. This has been effective for awhile, but suffers from diminishing returns for a bunch of reasons as bandwidth demand accelerates. High-traffic areas are, for the most part, in urban centers where deploying and operating equipment is more expensive, and where space can be difficult to obtain.
And as the density of macro cells increases, interference become much more difficult to manage with per-sector throughput declining as a result.
A different approach is needed to deliver an increase in capacity of the magnitude sufficient to deal with out-of-control data traffic. This approach is predicated on lower-power, shorter-range equipment such as Smart Wi-Fi access points or 4G small cells installed closer to subscribers, in dense deployments.
By limiting the range, the impact of interference is reduced while capacity density is increased. A single sector in a macro cell may have a comparable capacity to a Wi-Fi access point or a small cell, but it spreads it over a larger area, leading inevitably to lower capacity density.
To address these issues, mobile operators are looking at anything and everything including:
- Upgrading the 3G HSPA network where it makes technical and financial sense, but realize that this does not provide the increase in capacity that is required in high-traffic areas,
- Building a Wi-Fi underlay network for mobile data offload to address the immediate need for additional capacity,
- Purchasing more RF spectrum as operators move to macros LTE to establish coverage, promote device adoption, and maintain access for high-mobility users,
- Rolling out a small-cell LTE underlay network to provide additional capacity where needed, once LTE device adoption takes off. The small-cell LTE network complements the Wi-Fi network (and to a large extent it is expected to cover the same high-traffic areas) and the LTE macro network (mostly deployed for coverage and high-mobility access) to provide an additional capacity boost, and
- Using 5GHz Wi-Fi for NLOS backhaul as lots of smaller cells make it nearly impossible to run expensive fiber or firxed broaddband connections everywhere.
Small cell deployments are one of the most popular long-term strategies of mobile operators worldwide because they provide the capacity boost needed in the near term, along with the flexibility and compact form factor needed for highly-localized deployments in high-traffic environments.
Mobile operators no longer see Wi-Fi offload and small cells as competing solutions. They realize both are needed with each playing an important role within a multi-RAT, multi-layercellular network – spanning from macro base stations at one end to residential femto cells at the other.
Once a mobile operator has Wi-Fi offload infrastructure in place, it has done most of the hard work to roll out LTE small cells. Thanks to its early Wi-Fi “land grab”, it has secured a network of permitted Wi-Fi access points and small cell sites, with power, backhaul, and lease agreements, ahead of its competitors without Wi-Fi offload.
Access to small cell mounting real estate is crucial to keep installation and operation costs down, and to reduce deployment times.
Not only can Wi-Fi and LTE operate side by side, but they completely complement each other in an integrated deployment strategy, delivering the highest capacity increase afforded by next generation radio technology and spectrum availability, combined with the lowest TCO.
The initial deployment of an IEEE 802.11n Wi-Fi offload solution (if it’s Smart) provides mobile operators with an immediate capacity increase, available to most data-centric devices already in the hands of their subscribers.
But, equally importantly, the Wi-Fi infrastructure provides the foundation on which mobile operators can realize their longer-term data strategy, by establishing a network of sites that can be shared by Wi-Fi and LTE small cells. Once they decide to roll out LTE small cells, operators can simply add an LTE small module to their Wi-Fi access points – sharing lease costs and backhaul capacity.
This small cell strategy looks to deliver BIG time benefits.