Mobile Technology
Carriers look to harness hotspots

Mobile Technology

Mobile operators want to provide as much bandwidth as possible for their
third-generation (3G) network subscribers, especially in locations
likely to see high densities of mobile users. Both T-Mobile and Vodafone
have announced plans to enhance that coverage through the use of the
public access wireless LAN (WLAN) hotspots now proliferating at sites
such as airport terminals, railway stations, hotels and coffee shops. O2
and Orange are expected to follow suit at a later date.

But
despite the operators public commitment to the integrated 3G/GPRS/Wi-Fi
data service model, there are still questions about how calls will be
handed over from one type of network to the next, and how operators will
charge for such calls, according to analysts.

The idea behind the
integrated service is that when a 3G or GPRS subscriber moves within
range of a hotspot access point, they will automatically switch from the
cellular network over to the WLAN which in theory provides greater
bandwidth, up to around 5Mbit/s, potentially
at lower cost.

Actual data rates will vary according to the specification of the WLAN
equipment in use whether based on 802.11b or 802.11g and the number of
other users accessing the hotspot simultaneously.

In the early
stages at least, the Wi-Fi connectivity will not be built into the 3G
data card or handset, but will rely on the user having a Wi-Fi adapter
already installed in their notebook PC.

T-Mobile said that data
cards with trimode 3G/GPRS/Wi-Fi connectivity should emerge within the
next year or so.

“We are looking for something that creates a
seamless connection between 3G, GPRS and WLAN services irrespective of
the bearer,” said T-Mobile UK marketing director Sandy Munro.

This years Cebit IT show saw T-Mobile outline plans to introduce a
combined 3G/GPRS/Wi-Fi roaming service across the 700 Wi-Fi hotspots it
owns across Europe. Vodafone does not own its own hotspots, but it is
aiming to provide similar coverage through partnerships with third-party
hotspot providers.

“In a short period of time we will integrate
Wi-Fi onto the Vodafone 3G network, although it depends on provisioning
through partners,” said Vodafones UK chief executive, Bill Morrow. “In
the UK we are partnering BT Openzone, which has 850 wireless hotspots
across the country.”

However, analysts said there are still a
number of obstacles hindering the advance of 3G/Wi-Fi services.

“Despite optimism about the technology and confidence in dual-capability
wireless networks supporting both 3G and Wi-Fi, service providers are
still grappling with basic business questions, such as what the sources
of revenue will be, how services will be priced and bundled, and how big
the potential market is,” said Richard Webb, lead analyst for wireless
LANs at industry watcher Infonetics Research.

First, operators
need to decide when calls stop “belonging” to the cellular operator, and
start to belong to the hotspot provider, for charging purposes, and how
best to share or swap subscriber login details and customer information.

Nor has it been conclusively proven in a commercial environment that data
calls can be seamlessly handed over from one type of network to another.
Whether the user has to log in again, or whether any data session in use
during the transition will be interrupted are both questions that remain
to be answered.

Because it operates its own hotspots, T-Mobile
should theoretically be better placed to provide its customers with an
integrated 3G/GPRS/Wi-Fi service, according to Lars Westergaard,
research manager for wireless communications at analyst firm IDC.
“T-Mobile could enable that seamlessness more quickly, with a better
pricing structure of WLAN,” he said. “One should expect that Vodafone
should be more keen on routing traffic on its mobile network rather than
the WLAN.”