1 / 8

Main achievments

LOOP. Main achievments. Valdemar Monteiro. Outline. Problem and motivation Cross-layer proposal and results INTEROPERABILITY Conclusions and future work. Scenario Description Common coverage scenario with UMTS cell and with a WiFi hot-spot

jirair
Download Presentation

Main achievments

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. LOOP Main achievments Valdemar Monteiro

  2. LOOP Outline • Problem and motivation • Cross-layer proposal and results • INTEROPERABILITY • Conclusions and future work

  3. LOOP Scenario Description Common coverage scenario with UMTS cell and with a WiFi hot-spot IP-based core network assumed that acts as the bridge between WiFi, and HSDPA NRTV services that can be streamed either over HSDPA, or WiFi system

  4. LOOP RAT selection for HSDPA and IEEE 802.11e-Novelties of Algorithm RAT selection based on load suitability where the systems are HSDPA and WiFi, under delay constraints services Concept of suitability is used in terms of preferred access system to accommodate the service, where Suitability can change as load increase; So, the goal is to optimize the load in each RAT, measuring the diversity gain in quality of service (QoS) provisioning

  5. LOOP RAT selection for HSDPA and IEEE 802.11e- Algorithm description Suitability calculation for load balancing among cells of different RATs when new call is requested; Targeted to flexible traffic Flexibility imposes on the system, meaning that the service can be held by each RAT LThj LThj is the threshold load for RAT j

  6. LOOP RAT selection for HSDPA and IEEE 802.11e- Results and Scientific Impact Gain of 60% on the supported QoS load achieved with the CRRM (intelligently adapted algorithm) over HSDPA alone Scientific impact Exploring Common Management of the whole RR such mobile assignment of to different RAT is flexible, considering specific advantages of each system

  7. LOOP Conclusions and future work Our IEEE 802.11e event driven simulator is a tool that allows for tuning-up several parameters like the ones related to how to use block acknowledgment, normal acknowledgment, and no acknowledgment policies. The use of small CW for the VO access category may not be a very good idea since when the number of stations is higher than 38 the goodput starts to decrease due to a small CW size. By suffering collisions successively the retransmission threshold is overcome causing the increase of packet losses. The proposed cross-layer algorithm, showed very good improvements for VO traffic as it supports at least 13 extra stations. Regarding results for VI traffic, an improvement as shown but it is not significant. We conclude that this algorithm still needs some tuning in order to produce better results, although the results are already very promising.

  8. LOOP Conclusions and future work (cont.) • This simulator • enables simulations accounting for inter-working with WiMAX and HSDPA (in the context of the IT-MOTION tool) • allow for testing improvements on scheduling algorithms and Common Radio Resource Management (CRRM) techniques • In future work, the results with mixtures of applications and block acknowledgement will be addressed. Handover policies between APs will also be an objective to be fulfilled, where a scenario using more than one cell can be supported. Later, our simulator will be integrated into the IT-MOTION simulator, and further work will be performed to optimise inter-working among different systems (e.g. Wi-Fi, HSDPA, and WiMAX).

More Related