| 1. |
- Gunnarsson, Fredrik, et al.
(författare)
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Admission Control in Cellular Radio Systems Based on Relative Load Estimates
- 2001
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Ingår i: Proceedings of the Third Conference on Computer Science and Systems Engineering. - Linköping : Linköping University Electronic Press. ; , s. 163-168
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- When operating a cellular radio system nearly at full capacity, admitting yet another user may jeopardize the stability of the system as well as the performance of the individual users. Therefore, proper admission control is crucial. The core idea in this work is to predict the relative load of the system, given that a user is admitted. Then, the user will be admitted if the predicted load in the specific cell, and in its neighbors, is below some threshold. This provide an interesting alternative to algorithms based on hard capacity, which might be utilizing the resources inefficiently in order to be robust. The proposed uplink admission control algorithm utilizes measurements readily available in the system. Simulations indicate performance improvements. Furthermore, multi-services are naturally handled, and availability of high data-rate services are automatically limited with respect to coverage, compared to services of lower data-rate.
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| 2. |
- Gunnarsson, Fredrik, et al.
(författare)
-
Uplink Admission Control in WCDMA Based on Relative Load Estimates
- 2002
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Ingår i: Proceedings of the 2002 IEEE International Conference on Communications. - Linköping : Linköping University Electronic Press. - 0780374002 ; , s. 3091-3095 vol.5
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Konferensbidrag (refereegranskat)abstract
- When operating a cellular radio system at nearly full capacity, admitting yet another user may jeopardize the stability of the system as well as the performance of the individual users. Therefore, proper admission control is crucial. Prior art includes algorithms which are limiting the number of users or the uplink interference per cell. Both are known to yield roughly the same performance, but the former is difficult to configure, and the latter is based on a quantity, which is hard to measure accurately. The core idea in this work is to predict the relative load of the system directly, given that a user is admitted. Then, the user will be admitted if the predicted load in the specific cell, and in its neighbors, is below some threshold. The proposed uplink relative load estimate is focused on WCDMA. It utilizes measurements readily available in that system, either periodically scheduled or from handover events. Multi-services are naturally handled, and availability of high data-rate services are automatically limited with respect to coverage, compared to services of lower data-rate. Simulations indicate that the admission control operates satisfactory in different traffic situations with a universal parameter setting. Furthermore, the reporting overhead with periodical measurements can be avoided, since handover event-driven measurements yield roughly the same performance.
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| 3. |
- Gunnarsson, Fredrik, et al.
(författare)
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Uplink Transmission Timing in WCDMA
- 2003
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Ingår i: Proceedings of the 58th IEEE Vehicular Technology Conference. - Linköping : Linköping University Electronic Press. - 0780379543 ; , s. 1688-1692 vol.3
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Konferensbidrag (refereegranskat)abstract
- In wireless network uplink communications, there is a trade off between transmission coordination to avoid overload situations, and distributed transmission decisions to adapt to fast channel variations. Here, uplink transmission timing (UTT) is proposed as a scheme to allow some load control support, while transmitting mainly when the channel is favorable. It utilizes channel state feedback in the form of power control commands, which already are available in the system. Simulations illustrate the transmission timing behavior, and also indicate that UTT is a power and intercell interference efficient scheme to transport data compared to traditional dedicated channels with continuous transmissions and to schemes where transmission decisions are random.
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