UMA has been quoted as a main competitor of femtocells. Both can provide good indoor coverage to deliver high quality voice calls in a secure and easy to use manner. Suitably equipped handsets can make and receive calls using the same user interface, pressing the same buttons and using the same address book as when outdoors. But femtocells also offer to solve the data capacity crunch, offloading vast amounts of data traffic from more expensive outdoor cellsites. This is a somewhat different business case that needs closer examination.
First - a quick recap on UMA
UMA (Unlicensed Mobile Access) is a commercially deployed solution that delivers the same mobile voice and text message services over any Wi-Fi access point. It requires an extra box in the network (Kineto Wireless provided the market leading solution here) and special software in the handset. A range of handsets did incorporate the UMA software stack, including many smartphones from RIM Blackberry. There’s even an iPhone application you can download too. It’s principally aimed at voice, text and lowish rate data services for smartphones – you probably wouldn’t use it for mobile broadband with a USB data dongle for example, but it would be fine for email.
Unlike some other Wi-Fi voice solutions, it’s highly secure – the connection is encrypted and secured between the handset and the box in the network.
The competition between femtocells and UMA as a voice solution in areas of poor coverage/reception comes down to:
- UMA: Works with any Wi-Fi hotspot (so hotspots aren’t specific to any operator)
- Femtocells: Work with any 3G phone (so not limited to subset of UMA capable phones)
- Other claimed advantages for femtocells would include their better control of the radio spectrum (no interference from other unlicensed equipment, baby monitors etc.), longer battery life for handsets and better handling of large numbers of users (although more expensive Wi-Fi access points do this much better than the cheapest domestic ones).
Some users have found UMA to be particularly attractive when travelling abroad. By using UMA through any local Wi-Fi hotspot, they can make and receive calls as if they were at home (saving substantial costs of roaming charges).
My own experience has been that Wi-Fi provided in busy public environments has been of very poor and variable quality, certainly inadequate to guarantee receiving a call and keeping the connection for any length of time. Wi-Fi in less congested environments, particularly at home or office and sometimes in hotels, is generally quite good and more than adequate for this purpose.
It seems to me that the industry is retaining but not growing UMA at this time – there are a number of service providers who continue to offer it (such as T-Mobile USA and France Telecom/Orange in Europe). As the number of handsets continues to grow, it remains a proven and viable option for operators.
Mobile Broadband Data Offload
With data traffic growing at an ever increasing rate, many operators are looking at ways of reducing the strain by encouraging their customers to use Wi-Fi hotspots where possible. Sprint have mandated that all new smartphones sold must be Wi-Fi capable. AT&T operate many 10,000s of hotspots around the US which their customers can use for free – recently highlighting this again with a “hotzone” providing better capacity in Times Square.
Such use of Wi-Fi for data doesn’t require any special UMA software stack in the phone. This is only used by data services, such as email, web browsing and some downloaded applications. I have to say from personal experience that it makes watching YouTube videos and similar a much more pleasurable experience when using a well connected hotspot compared to a poor 3G connection.
So what are the drawbacks for using Wi-Fi broadband in your smartphone or laptop?
Many people may not fully appreciate just how insecure Wi-Fi can be, especially in public areas. In most cases, Wi-Fi encryption is not used in public hotspots, so your data is commonly transmitted “in the clear” including your email address and password and any webpages you view. Only when viewing secure webpages (using HTTPS with the browser padlock showing) or when connected via a corporate VPN is your data really hidden from prying eyes. Some email clients do use the secure login method (assuming your ISP supports this), which would also hide your email account details. Specially designed systems, such as RIM Blackberry email, are inherently secure and don’t suffer from this issue.
A security consultant reported a scheme which could poison your browser cache during a Wi-Fi session, leaving your laptop or smartphone insecure even after leaving the area.
I think it may only take one or two high profile media scare stories to awaken the wider public to this gaping hole in their personal information security. This is a disaster waiting to happen…
Can Wi-Fi systems fix these problems?
There are four major issues with Wi-Fi data offload in public hotspots today:
- The need for a connection manager software to be downloaded onto your device
- Automatic discovery of hotspots (do you find you’re often prompted whether you want to connect to a particular hotspot – or worse to a “Free Public Wi-Fi” virus site)
- Authentication (do you have to enter your username/password and/or credit card details?)
- Service Continuity – mobile operators lose control of their customers sessions when they use Wi-Fi, and many premium content services may no longer be accessible
The solution proposed here is to use the SIM card authentication already in place for the mobile network when connecting to a hotspot. This should be as seamless an experience as connecting to a 3G basestation, and also match the security.
However, this isn’t a trivial upgrade. It requires extra/different software in the mobile device, some extra software in the Wi-Fi hotspot and a signalling controller box in the mobile network. Swisscom (who operate many Wi-Fi hotspots in several countries as well as fixed and mobile networks in Switzerland) have been exploring this approach for many years, but it hasn’t captured the industry’s imagination.
There are also other approaches not discussed in the white paper, such as the connection manager software from Boingo and iPass which run on (mainly) corporate laptops. When used with a corporate VPN system, these provide secure business connections including automatic discovery of supported hotspots. This approach works for laptops although I’d say is much less appropriate/common for smartphones.
Femtocells solve separate issues for poor voice coverage, poor data coverage and addressing the high cost of mobile data capacity. In each case, Wi-Fi may be promoted as a competitor using different technology.
In some cases, such as secure use of Wi-Fi in the home, femtocells have strong competition – probably more for laptops than for smartphones. In many public areas, I’d say that Wi-Fi falls short of delivering high capacity, seamless and secure data connection – especially in areas of heavy use.
In order to match the seamless and secure capabilities of femtocells, Wi-Fi systems will need to solve several technical issues. While there are are solutions for these, unless the pace of their adoption by network operators increases, femtocells will continue to look a more attractive option.