C OMPARECENCIAS ANTE EL P LENO

In this subsection two other profiles, the Interactive Background Balanced (IBB) and the Interactive Oriented (IAO) profiles, with different services’ penetration percentages and QoS priorities, are analysed, the results being compared with the ones from the default scenario. In these profiles, the influence of P2P is reduced to represent a more daytime approach, as the E-mail and Chat services are usually more used throughout the day. On the contrary, the P2P service is somehow a night service, as operators offer the so-called “Happy-Hour”. In the alternative profiles, Streaming is considered the service with the highest QoS priority, followed by Web, while E-mail is considered the service with the lowest one. The modifications in the QoS priority list is an additional factor that influences the results presented in this subsection.

Analysing Table 4.6, where the services’ characteristics are shown, one can notice that the alternative profiles present a significant reduction of the percentage of P2P users. P2P is highly demanding service, since it is characterised by high file size and, due to the low throughput tolerated, high session duration. On the other hand, there is an increase in the percentage of users performing Chat, E-mail and FTP. Both alternative profiles are more user throughput demanding, mainly due to the increase of E-mail and FTP users, since these services have a higher maximum, thus, a higher average throughput per user. The IBB profile is the most demanding one, as the reduction from IBB to IAO for P2P is more meaningful than the increase in the percentage of Chat in the IAO profile.

Table 4.6. Default and alternative scenarios characterisation.

Penetration

Percentage [%] Penetration Percentage [%] Services

Default Scenario

QoS priority

IBB Profile IAO Profile

QoS priority Web 46.4 1 40 40 2 P2P 42.3 6 10 5 5 Streaming 6.2 2 10 10 1 Chat 3.1 5 10 20 3 E-mail 1.0 3 20 15 6 FTP 1.0 4 10 10 4

One can notice from Figure H.7a) that the average network throughput remains approximately the same for the IBB profile, with a reduction below 1%, while for the IAO one, there is a reduction of 3.5%. In the default scenario, the average network throughput does not exceed 2.4 Mbps, as seen in Subsection 4.3.2. Regarding the alternative profiles, although being more throughput demanding, the

average throughput network does not increase. One can say that, for approximately 1600 users and using the randomly distributed user’s throughput, the maximum average network throughput is 2.4 Mbps. The average network radius is reduced by 2.8 and 2.5% for the IBB and IAO profiles, respectively, Figure H.7b).

In both alternative profiles, there is a reduction of the average ratio of served users, of 6 and 10% for IAO and IBB, respectively, Figure 4.15a),mainly due to the fact that fewer P2P users are considered. P2P has the second lowest minimum throughput, hence, these users can be reduced several times before being delayed – when the user throughput crosses the minimum threshold – leading to a lower probability of the user being delayed. So, in a P2P dominant profile, as the default one, fewer users are considered delayed, and since P2P has a high percentage of users, this effect is more perceptible. The reduction of the number of users, together with the low reduction of the network throughput, leads to an increase of 13.9 and 3.6% for the IBB and IAO profiles, respectively.

For the difference observed in the alternative profiles regarding Chat and E-mail, the same justification is valid. In the IAO profile, there are more users performing Chat, which has the lowest minimum throughput, and so more users can be served than in the IBB one, Figure 4.15a). The average satisfaction grade increases to 89 and 90% for the IBB and IAO profiles, Figure H.8a), as the ratio of served users decrease and so, fewer users are served, allowing each one to be served with a higher throughput.

0.40 0.45 0.50 0.55

Default IBB IAO

Profile Averag e Rat io o f Served Users 0 100 200 300 400 500 600

Default IBB IAO

Scenario T o tal N u m b er o f U ser s p er H o u r [ x 1000]

(a) Average Ratio of Served Users. (b) Total Number of Users per Hour. Figure 4.15. HSDPA parameters (Ratio of Served Users and Number of Users) for the 3 profiles

studied.

Regarding the total network traffic per hour, and even though the alternative profiles have higher throughputs, there is an increase of near 18.5% for the IBB profile while in the IAO one, the average network traffic actually decreases 1%, Figure H.8b). For the Node B analysis, the traffic increases to 0.44 GB/h for the IBB profile, while being reduced to near 0.37 GB/h for the IAO one. This is due to the higher percentage of P2P users in the default scenario, whose sessions are characterised by high data volume data. In the IAO profile, there is a reduction of the carried traffic per hour, compared to the default scenario, since the P2P percentage is only 5%, and compared to the IBB profile, the former has more users performing chat, a low volume service, and fewer performing E-mail. The reduced

P2P percentage also explains Figure 4.15b), where there is a large difference in the number of user per hour. In the IAO profile, there is an increased of 943% regarding the number of user served per hour while for the IBB profile, this increase is even higher, 1265%. This difference to the default scenario is due to the higher percentage of services characterised by low data files, hence, shorter session durations. In the busy hour analysis per Node B, more than 1900 users are served in the IBB profiles, while for the IAO one, the number of users is near 1500.

The difference between the number of users per hour in the alternative profiles is also explained by the higher average instantaneous throughput per user of the alternative profiles, as a higher throughput per users leads to a lower average session duration, and to a higher number of users served per hour.