Rodrigues, E.B.; Casadevall, F.;
Technical University of Catalonia
This paper appears in: Communications Magazine, IEEE
Issue Date: September 2011
Volume: 49 Issue:9
On page(s): 90 - 98
Digital Object Identifier: 10.1109/MCOM.2011.6011739
Date of Current Version: 08 September 2011
Sponsored by: IEEE Communications Society
Full article access:
IEEE Xplore - Control of the trade-off between resource efficiency and user fairness in wireless
There is always trade-off between channel efficiency and user fairness in the wireless system. For those reader who are familiar with wireless communication should know that in order to achieve maximum channel efficiency, we should use the best channel available. However, there are some users who only have the worst channel will have very poor performance under this policy. If the system share some of the channel to the poor channel, then everyone will have acceptable service but the channel efficiency will be lower.
Although from a network operator perspective, it is better to have higher channel efficiently as it can maximize the revenue, the network operator cannot ignore the requirement from customers that they need to have fair resource allocation so that they are not in a starvation/outage situation and their quality of service (QoS) requirements are guaranteed. Therefore it is better to have a balance between them.
This article divide the network services into non-real-time (NRT) and real-time (RT), where RT services require low and bounded delay, and NRT services require overall high throughput. The authors proposed the Adaptive Throughput-Based Fairness (ATF) policy, which is an adaptive version of the utility-based alpha-rule, for NRT services, and Adaptive Delay-Based Fairness (ADF) policy, which is an adaptive version of the utility-based beta-rule, for RT services. They also provide simulation result of this two policy with comparison with other policy.
Since Beggar A is the user of the wireless network, Beggar A would like to focus on the user fairness perspective. The new policy proposed by the authors can allow the operator to provide fairer network with less scarification on the channel efficiency. It was a good try, but the result is not appealing, therefore further development on this policy is required.
One important point need to keep in mind is, even under the fair policy (i.e.: Cell Fairness Index equal to 1), the performance of the worst channel cannot improve much, but the performance of the best channel decrease much. Therefore, Beggar A believe that it is better to improve the channel quality then rely on fair policy as fair policy can only be a compensation on performance to the worst channel.