Hong Kit, how much is this driving internet traffic on the international links?
HK: Before 12 months ago, a lot of mobile operators were under their mother company, which also owned a fixed-broadband service, for example, and they were bound together because the traffic was relatively small. After 2008-2009, they began to have high enough growth demand that they were able to spin off, and they could come directly to us to buy IP transit. And in the past 12 months, some of the customers have doubled their bandwidth. Traffic growth for our mobile customers has been 100% to 120%.
What kind of impact is all this having on the mobile IP architecture?
CD: Well, we have HSPA+ and all-IP to the cell sites, and if you have fiber or high-capacity microwave, there's no bottleneck with the radio access or backhaul. For the core, at this stage it has been a bit easier to grow the capacity. There will come a point where you want to simplify your core, but I don't think the complexity is at this level today.
SC: I agree. In Hong Kong, there's not as much concern about network loading because we've already been building up the network to accommodate the traffic to meet the broadband need, not just the mobile usage.
AG: One thing that we found in Telstra, because we've got a common core for our 3G network and HSPA+ network, as we went through the speed evolution, we would find parts of our IP network that were in fact causing bottlenecks, and they weren't exposed until the air interface speeds went up. So there are bottlenecks within your core that you just don't know are there, and we need to look at how we can identify those and remove those in a cost-effective manner.
Given all that, just how urgent is it for mobile operators to migrate to a flat-IP architecture with LTE?
CD: I think it's a question of volume and throughput. And right now at 21-Mbps, I don't see it as a bottleneck. There is the claim that with flat IP or LTE, we'll get better 10-20 millisecond latency vs the over-100-millisecond latency we have now. That would make a big difference, but I think a lot of it is due also to the LTE radio access and NodeB.
AG: No one's going to pay the engineers to make it flat for the sake of being flat. We're not loading things onto our existing network, we're unloading things off. So we're doing incremental things at the moment and it'll take a technology change to really move to true flat architecture.
SC: It has to be something that's justified. When LTE is ready, should we then jump on it? My question is still: why? By all means, if there's a good reason to get a much more efficient network architecture, you can always do that. It's not a question of technology; it's a question of business evaluation.