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Improved TDD resource allocation through inter-mobile interference avoidance
KTH, Superseded Departments, Signals, Sensors and Systems.
2001 (English)In: IEEE Vehicular Technology Conference, Rhodes, 2001, Vol. 2, no 53ND, 1027-1031 p.Conference paper (Refereed)
Abstract [en]

Time division duplex systems, in a convenient way, facilitate the implementation of asymmetrical links which are required to efficiently handle the increasingly asymmetric traffic offered by current and future wireless applications. If boundaries between uplink and downlink time-slots are not synchronised among cells, e.g. when different asymmetries are required in different cells, Inter-Base station (IB) interference and Inter-Mobile (IM) interference arise. To keep the outage probability at a reasonable level this interference needs to be avoided. In a system with centralised resource allocation, information about IM link gains can be used to estimate IM interference. Measuring all IM link gains is often considered to be an intractable task. Thus, in this paper a simple method to estimate IM link gains and to avoid IM interference is proposed and evaluated. In centralised system, for the critical case of heavier downlink traffic, the new method significantly improves system capacity.

Place, publisher, year, edition, pages
Rhodes, 2001. Vol. 2, no 53ND, 1027-1031 p.
Keyword [en]
Probability, Resource allocation, Telecommunication links, Telecommunication traffic, Inter-base station interference, Inter-mobile interference avoidance, Signal interference
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
URN: urn:nbn:se:kth:diva-25408OAI: diva2:357990
IEEE VTS 53rd Vehicular Technology Conference (VTS SPRING 2001); Rhodes; 6 May 2001 through 9 May 2001
QC 20101020Available from: 2010-10-20 Created: 2010-10-20 Last updated: 2010-10-21Bibliographically approved
In thesis
1. Demand responsive resource management for cellular networks: link asymmetry, pricing and multihopping
Open this publication in new window or tab >>Demand responsive resource management for cellular networks: link asymmetry, pricing and multihopping
2005 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

Economic affordability of services and infrastructures has rapidly become one of the key issues in the evaluation and design of wireless access systems. The provisioning of high data rates, at an ``affordable'' price, constitutes a serious challenge to the structure and management of current and future wireless networks.

The management of radio resources, Radio Resource Management or RRM for short, has traditionally been benchmarked mostly by technical merits such as throughput (data delivery capability) and Quality of Service (QoS). When comparing different RRM schemes, the scheme that can deliver more bits per Hertz (unit of bandwidth) or per Euro is often assumed the more efficient. From an economic point of view, however, cost efficiency is not equivalent to profitability.

We conjecture that the economic efficiency and profitability can be improved both by better technical efficiency and by better accounting for users' service appreciation and willingness to pay. While we shall, primarily treat the operator's benefit of improved RRM, we will try to improve the RRM by means of being more responsive to the demands of the users. In eight conference and journal papers, we investigate: Provisioning of support for asymmetric traffic, Quality and pricing aware resource management and Creation of forwarding incentive in multihop cellular networks.

We show that implementing support for asymmetric links can improve the efficiency of (service) production in Time Division Duplexing (TDD) mode wireless networks with asymmetric traffic. That is, more traffic can be handled with the same system resources. Compared to Frequency Division Duplexing (FDD), TDD offers more flexible use of spectrum resources. The benefits of TDD and support for asymmetric links are readily available for systems providing high-rate spotty coverage. For systems aiming at full coverage and tight reuse, however, proper measures must be taken to control inter-mobile- and inter-base-station-interference.

We present the MEDUSA model framework for taking users' service appreciation and willingness to pay into account in performance evaluations of wireless networks with elastic traffic. Assuming that user satisfaction depends on both the quality and the price of the service, numerical experiments show that the economic efficiency of an RRM scheme is affected by the pricing scheme. We also introduce the concepts of speculative resource management to exploit traffic elasticity and improve resource utilisation. With speculative admission control, users with good propagation conditions may be admitted to a full system at the expense of a slight degradation of the QoS of some or all users, if the expected total revenue would thereby increase. Results indicate significant revenue gain with speculative admission control. Service perception aware scheduling was evaluated as a means to improve resource utilisation, but yielded only marginal gain compared to a weighted proportional fair scheduler.

For the third area studied in this Thesis, i.e. multihopping in cellular networks, economic efficiency was both the goal and one of the means to achieve it. By means of a resource re-distribution scheme called Resource Delegation we eliminated the bandwidth bottle neck of the relays. We combined Resource Delegation with economic compensation for the energy expenditures of the relays and were able to achieve significantly increased operator revenue with maintained or improved user utility. Assuming that the added complexity of keeping track of reward transactions is negligible, profitability was correspondingly improved.

Place, publisher, year, edition, pages
Stockholm: KTH, 2005. viii, 90 p.
Trita-S3-RST, ISSN 1400-9137 ; 0509
Electrical engineering, Elektroteknik, elektronik och fotonik
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
urn:nbn:se:kth:diva-180 (URN)
Public defence
2005-04-29, Sal C1, Electrum, Isafjordsgatan 22, Kista, 14:00
QC 20101021Available from: 2005-04-27 Created: 2005-04-27 Last updated: 2010-10-21Bibliographically approved

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