Smartphone Users: Say Hello to Femtocells
Small Localized Base Stations are Vital to the Future of Smartphones
Aug 21, 2009
The Apple iPhone, the Palm Pre and the myriad cool but data-intensive smart phones – as well as tablets, netbooks and the rest of the surging army of mobile devices -- are forcing the hands of the AT&Ts, T-Mobiles, Sprints and Verizons of the world. The simple fact is that cellular networks must find a way to deal with the flood of data that threatens to overwhelm them.
This threat will grow. One sign of the great amount of bandwidth that will be consumed is that we already are moving toward the next networking standard, 4G. Yes, the rein of 3G was short. The fact is that people own multiple devices – and their consumer electronics gear, cars and even appliances are increasingly connected.
Supporting the Pre, the iPhone and the Others
All this connectivity has the carriers scrambling. One of the major tools in handling all the data is a modest looking little widget called a femtocell. Though they are already are out in the field – AT&T uses them in their @Home service – “femtos” are at the end of the trial and testing phase. Look for femtos to hit in significant number and become a fixture on the scene toward the end of this year and in 2010.
What is a femtocell, though? Conceptually, it’s easy to understand. Femtocells are little base stations that have much of the functionality of their “macro” big brothers out in the street. The main differences are that femtocells are small (in technical jargon, “teensy-weensy”) and are situated in the subscribers’ home or office.
The Meeting of the Internet and Cell Network
Femtocells help the carriers – and, in some ways, their subscribers – in a number of ways. The femtocells are independent of the main telecommunications network outside. Instead, they connect the subscriber’s wireless device to the homes digital subscriber line (DSL) or cable modem, which traffic the signals where they have to go.
This offers two financial benefits to the cellular carrier: The traffic to and from that subscriber device is “off loaded” – chucked off, in other words – the cellular network that is so crowded. This reduces stress on the main network and saves the carrier money. Since the femtos use DSL and modems, the subscriber pay to power them.
The second money saver is that the Internet or a similar network is used to carry signals back to the innards of the carrier’s infrastructure. This is free “unlicensed” spectrum – and thus far less expensive than the licensed flavors of bandwidth used in traditional “backhaul” operations.
The final benefit of femtocells is a biggie. The spectrum used to support each successive type of cellular networking – 2G, 3G, 4G (there even is a “2.5G”) – uses progressively higher frequencies. The higher the frequency, the more trouble the signals have permeating annoying obstructions like walls. The presence of femtocells alleviates this problem.
Femtocells certainly are coming. In addition to helping save the cellular carriers’ bacon, they create a platform from which it is much easier for wireless (Wi-Fi) and cellular services to be combined. In these scenarios, the network can easily decide whether a call or data session is best conducted on the cellular or wireless network based on variables determined by the subscriber or the carrier. Calls can even be switched as they occur.
For instance, a call originated in the home on the Wi-Fi network would automatically be switched to the cellular network when the caller leaves home. He or she would have to have the right phone to do this, however.
Femtocells offer advantages to everyone. Potential users should be aware, however, that they will be footing some of the bill that in the past was paid by carriers. It seems, in the final analysis, to be a relatively small price to pay for more robust mobile service.
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