LONDON -- LTE/EPC & Converged Mobile Backhaul -- Everything Everywhere Ltd. (EE) shared some of the challenges it faced and lessons it learned from launching the U.K.'s first, and only, 4G Long Term Evolution (LTE) service here at Layer123's industry conference dedicated to LTE and mobile backhaul on Tuesday.

EE launched LTE services on Oct. 30 using the 1800MHz spectrum that it already had for delivering 2G services. By refarming this spectrum for LTE services, the U.K.'s largest mobile operator with 27 million subscribers will be able to offer 4G services for at least seven months ahead of its rivals Telefónica UK Ltd. (O2), Vodafone UK and 3, which need to acquire LTE spectrum from the upcoming auction scheduled to start in early 2013. (See How Not to Do 4G, EE-Style, Euronews: 4G Arrives in UK, EE Unveils 4G Price Plans, Brits Braced for 4G and Euronews: Will UK Fast-Track 4G Auction?)

But it wasn't easy, as Mansoor Hanif, EE's director of network integration and LTE, explained.

Among the technical challenges EE faced were lack of device support, uncertainty about voice services and having to support two different legacy networks -- that is, those of Orange UK and T-Mobile (UK), as EE is the joint venture of France Télécom - Orange's and Deutsche Telekom AG's U.K. operations.

Hanif said that it was particularly difficult to convince device manufacturers to add support for EE's 1800MHz band in LTE smartphones. "To get some of them on board and get 1800MHz on their roadmaps involved endless negotiations, discussions and a lot of drama behind the scenes," he said.

Another issue for EE was how to deliver voice services by using the legacy 2G and 3G networks, which is referred to as circuit-switch fallback (CSFB). The operator knew its 4G service launch would focus on smartphones from the start, so it had to be able to deliver voice. But the problems were that there was no device ecosystem in place, especially for 1800MHz devices, to support CSFB and there were "serious doubts" about performance and call setup times. All this caused a lot of "nervousness" for the operator, Hanif said.

The backhaul network design was yet another challenge, which was made more difficult by the fact that EE has a network-sharing agreement in place with 3 for the transport network. That meant EE had to agree on the network design plans with its rival.

"To agree on best design [for backhaul] is a challenge, to agree on that with your competitor is another challenge," said Hanif.

4G lessons
Given all of those hurdles to clear, it seems a wonder that EE got its service off the ground when it did.

Here's what Hanif said EE has learned from the process:

• CSFB adds minimal call setup time and it's below the threshold for customers to notice. So there's no need to rush to VoLTE -- that is, the IP Multimedia Subsystem (IMS)-based way to deliver voice over LTE networks.
• There needs to be careful setting of radio idle times to optimize battery life while balancing signaling load and service performance. Operators have to look at that issue very carefully.
• The IPSec deployment was surprisingly more difficult than expected. "It caused us serious issues in terms of getting the network up and running," Hanif said.
• Backhaul decisions had to be optimized to meet tight deadlines and demand for coverage and high quality performance. So, EE opted for Gigabit Ethernet capacity from BT Wholesale and Virgin Media Inc. along with point-to-point, single-hop microwave links in its backhaul network. (See MBNL Backhauls With Virgin Media.)
• The LTE "uplink is fantastic, it's magnificent," he said. Indeed, Hanif said that the amount of data users have sent over EE's 4G network since it's been launched is the equivalent of uploading the "Gangnam Style" video 19 million times. [Ed note: Now, who wouldn't tire of that?]

-- Michelle Donegan, European Editor, Light Reading Mobile