IP characteristics for 3G and WiFi links
swmike at swm.pp.se
Thu Aug 26 14:37:27 CDT 2010
On Thu, 26 Aug 2010, Daniel Migault wrote:
> Parameter | Wifi (802.11a/g) | 3G (HSDPA)
> Latency 100 ms 60 ms
> Bandwidth 5 Mbps 3 Mbps
> Packet Lost Rate XXX XXX
So, if you want to emulate HSPA you need to understand how it works. If
you go from "idle" (30 seconds of not sending data) you will see 1-2
seconds of jitter as radio resources are allocated and brought "online",
until you can send packets. There are multiple states, either you have HS
resources, or you have regular 384k channel, or you basically have "none".
All of these have different characteristics.
Packet loss on 3G is really low as it does re-sends itself, normally you'd
see muc less than 1% of packet loss, usually a lot lower than that. There
is quite a lot of resending and assuring packets are not lost on multiple
layers beneath IP in those networks.
Mikael Abrahamsson email: swmike at swm.pp.se
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