[LINK] NBN wireless latency

[stephen at melbpc.org.au]

NBN wireless latency "the same as 3G" 

By Renai LeMay  Wednesday, 01 June 2011 15:38 
<http://www.itwire.com/it-policy-news/government-tech-policy/47549-nbn-
wireless-latency-the-same-as-3g>


The National Broadband Network Company today provided further details of 
how its Ericsson-backed national wireless network was expected to perform 
technically, with chief technology officer Gary McLaren stating the 
network was expected to perform at least on par with existing 3G mobile 
networks when it came to network latency.

NBN Co has previously declined to say what levels of latency can be 
expected from the fixed wireless technology.. in the wake of concerns the 
technology might be a step backward from what is currently offered by 
ADSL2+ fixed broadband.

The ADSL broadband currently used by most Australians typically, 
according to network experts, delivers a latency of between 10 and 50ms, 
while fibre broadband delivers a faster response time — between 15ms and 
25ms. 

3G mobile broadband can deliver much slower latency — for example, recent 
testing in Sydney’s CBD of Telstra’s Next G network showed an average 
ping time of 85.5ms to local servers, using one of Telstra’s Elite USB 
modems.

The Long-Term Evolution technology being implemented by mobile operators 
like Telstra will also be used in NBN Co’s wireless network, and has the 
potential to cut latency drastically — as low as 10ms.

Speaking at a press conference today, McLaren said latency on the 
wireless section of the NBN would be “more or less the same” as it was on 
3G mobile networks.

The executive declined to provide numbers until NBN Co conducted trials 
of the rollout. However, “it certainly won’t be any worse,” McLaren 
said. “We really expect it to be at least the same, if not a little bit 
better.”

McLaren also provided further information on the likely speeds of the 
wireless network, noting the 12Mbps speeds outlined under the 
Government’s NBN policy were peak network speeds, with some network 
contention expected to cut that down a bit in reality.

However, the CTO added, users could expect to see dramatically better 
speeds than were available on some mobile networks. “We will be 
engineering it so that at least 512kbps will be available for everyone, 
and we expect to see quite a bit more,” he said, appearing to refer to 
the portion of the backbone link to each wireless base station that each 
individual premise connecting would be able to access in a guaranteed way.

McLaren emphasised that the fact that NBN Co was optimising the network 
for fixed connections on the side of buildings rather than roaming mobile 
use meant that NBN Co’s wireless network would preform much better in 
general than comparable 3G mobile broadband networks. “So we’ll actually 
see very good typical speeds,” he said. “That engineering of the capacity 
is probably ten times more than many mobile networks today.”

A number of trials of LTE services have shown theoretical speeds of up to 
100Mbps. But although McLaren acknowledged NBN Co would look at higher 
speeds in future, for the moment it wanted to focus on delivering 12Mbps 
speeds in a predictable and reliable way.

“That figure of 100Mbps or whatever it is is obviously highly conditional 
on how many people are actually in the cell and using it, how close they 
are to the cell,” he said. “That lucky user … it may be there for a 
period of time, but over time as the network grows, they’ll see their 
service degrade. We’re about predictability, quality of the actual 
service, over trying to get maybe get access to people at higher speeds.”
--

Cheers,
Stephen