User's Manual

Table Of Contents
3 Detailed Description
APCD-LM043-4.0 43
To illustrate the output of the model, consider the following example. First of all, make the
following general assumptions:
LMS4000 900 raw channel rate is MHz 2.75 Mbps
There are no channel errors
Servers are fast and do not present a bottleneck
There are no external link or backhaul bottlenecks
TypicalCCUtoEUMrangeis0to3km
GOS is unlimited
Furthermore, assume that typical end-user traffic is Web browsing, averaging one 60 kbyte
HTTP transfer every two minutes. This traffic pattern is based on analyses of busy-hour data
collected from LMS systems consisting primarily of residential users. In normal usage, users
randomly and independently download a file or Web page, take time to process the
information, and then download another file or Web page. Assuming this type of traffic, the
performance shown in Figure 23 results.
Figure 23 Net Throughput per EUM 100 EUMs, 60 kbyte HTTP every 2 minutes
From Figure 23, each of the 100 end users can expect a net throughput better than 800 kbps
80% of the time, and better than 1.3 Mbps 20% of the time. You can also assess system
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Performance (kbps)
Probability that Performance was
Exceeded