Telstra is addressing the strain on its Next G network, caused by signing up 2.5 million new mobile customers in the last 18 months, with a number of upgrades — but the company believes that the network is still performing well.
As part of the company's rolling upgrade program to its Next G network, Telstra has completed 16 upgrades in the last six weeks in Sydney alone, and plans to do one every week for the next few weeks, Telstra's executive director of networks Mike Wright told ZDNet Australia.
"As we see the traffic go above the [key performance indicators], we've been planning these," he said. "We watch the traffic, look for areas of hotspots, organise the work and get it completed. [We] had a few more cells [with congestion] than we'd like, but we're starting to get them done now, where we're starting to get the upgrade work completed.
"As a general rule, the network is performing very well. I mean, we've added about two and a half million customers in 18 months, and the statistics across the network we're still pretty happy with, but we still have a few cells we're having to catch up on, where a practical issue slows things down."
In the last six months of 2011 alone, the company added close to 1 million more mobile customers, bringing the total number on the Next G mobile network up to 13.2 million, but users in the Sydney and Melbourne CBDs, in particular, have started reporting on Twitter and broadband website Whirlpool constant issues with data and call dropouts.
Telstra uses its monitoring tool, known as "Devil", which the company owns the worldwide patent to, to forecast expected traffic in particular cells in order to plan for upgrades to meet customer demands.
The upgrades can range from simply upgrading software to going to the cell site and plugging in a transceiver, which adds the next frequency to provide more spectrum for that cell, right up to installing a new antenna for the site. Wright said that Telstra would try to get these upgrades completed before customers noticed any impact on their service, but admitted that some practical issues, like getting permission from building owners or local councils, can delay some upgrades.
"Sometimes, though, some of that work — depending on whether it is a rooftop, or if it needs a new antenna — we think it'll take three months, and it takes four, so every so often, you'll get a cell that falls below the standard we would like," he said.
"If you bear with us for a little while, it'll come good pretty soon."
Although customer reports of problems with Next G have been centred around Melbourne and Sydney, Wright said that the growth in traffic on the Next G network has been fairly evenly distributed across the entire network.
Individual customer experience with Next G can vary depending on their device, he added, and in peak travel times in train stations, customers may also notice congestion.
Interference is also an issue from time to time, he said, with a cell in Melbourne's CBD having particular problems until recently.
"Last week, we discovered one particular area that was getting very bad performance all day until about 6 o'clock at night. What we found out was that there were some lights on a timer that were faulty, and they were generating interference back into the network," he said. "We normally see this in rural; it's unusual to find it in metro."
Refarming spectrum to meet demand
Rather than just building more network towers to meet the demand, Wright said that Telstra is looking to get more capacity into its existing towers by getting more spectrum and refarming existing spectrum.
Telstra is in the process of refarming 2100MHz spectrum from its joint network with 3 Mobile back to its Next G network. Most customers have been migrated off, he said, but the network will remain in operation until August. This has been causing some issues with a minority of customers.
"Some mobiles from time to time can find themselves back on that network, and they sometimes don't come back off it unless they turn their mobile on and off," he said. "We see that occasionally. It's a mechanism that can still occur. It's fairly unlikely, but still possible."
Wright said that the company is in discussions with overseas operators to refarm its 900MHz spectrum used for 2G now for long-term evolution (LTE) networks, but he said that this is a long way off.
"We don't see that as an immediate possibility. We're talking to different operators and chipset makers around the world, because we believe ultimately it is up to the operator community to reuse spectrum as efficiently as we can."
The traffic on Telstra's 2G network is down to around 10 to 15 per cent what it once was at the peak of its life, and 2G was still very popular with international roamers visiting Australia. Wright said that Telstra would keep part of the spectrum for 2G, but would refarm the rest for LTE.
"We don't see, and don't have any plans to shut 2G, but we believe, with the direction of the traffic has gone on it, we can compress the spectrum down," he said. "We see an opportunity to keep running a 2G layer, but very minimal to support the remaining services on it."