Channel Allocation Schemes Comparison for Priority Wireless Mobile Networks

1. Channel Allocation Schemes Comparison for Priority Wireless Mobile Networks By Dimas Gutierrez

2. Introduction • Wireless mobile networks growth. • New data technology ( text messaging, voice mail, videos, music, web browsing). • Data calls, voice calls , and handoff calls. • Primary goal is keep the call blocking probability low. • Different channel allocation schemes. • Preemptive approach, bandwidth allocation, real-time and non real-time calls, Dynamic priority, and Queuing.

3. Performance Analysis of Preemptive Handoff Scheme for integrated Wireless Mobile Networks. • Proposed a hybrid reservation handoff scheme with preemptive procedure for integrated real-time and non-real time service wireless networks. • Calls: • Originating real-time and non real-time service calls. • Real-time handoff and non real-time handoff. • Channels: • Real-time service calls (first priority). • Non real-time service calls. • Overflowed real-time and non real-time handoff requests.

4. System Model

5. Modeling an Efficient Handling of Handoffs in Integrated Wireless Mobile Network. • Introduced two handoff schemes: Non- Preemptive priority handoff and preemptive priority handoff scheme. • Non-Preemptive Priority Handoff Scheme considers each cell having a capacity of S channels. • Each base station has two queues Qv with capacity Mv and Qd with capacity of Md. • Incorporated handoff threshold and receiver threshold. • For data mobile users, there is no handoff area

6. System Model

7. On Handoff Performance for an Integrated Voice/Data Cellular System • Bandwidth allocation schemes were proposed to support multiple traffics . • Traffic Classification: • Complete Partitioning (CP ) • Complete Sharing (CS) or hybrid schemes • A voice and data intergraded with finite buffers . • the bandwidths assigned to voice and data were separated . • Dual Partition (DP) and Dual Threshold Bandwidth Reservation (DTBR). • Handoffs were not differentiated from new call .

8. DP and DTBR

9. A Channel Allocation Scheme with Dynamic Priority for Wireless Mobile Networks. • A fixed number of channels C is assumed and only a single cell. • Data transmission was classified in data calls, new voice calls, and handoff calls. • Cell capacity was divided in two blocks. • Introduced a second scheme to compare the results.

10. DPTQ & DTTQ

11. Analysis

12. Issues • No traffic model. • No description of how the DTTQ schemes manipulated the queues. • No specifications of new voice and handoff calls waiting time.

13. DPTQ & DTTQ

14. Modifications • Choose a lower data threshold. • Distribute the rest of the channels equally between the handoff calls and new voice call. • Increase the size of the data queue • Decrease the size of the voice and handoff queues. • Apply preemptive approach giving first priority to handoffs and second priority to the new voice calls, and third to data calls.

15. Proposed Scheme

16. Conclusions • To new scheme was proposed in this project to replace the DTTQ. • This new version is more realistic and explains clearly what happens when any type of call arrives and how the queues are used to decrease the blocking probabilities primarily of the new voice and handoff calls. • The size of the data queue was increased I order to be able to accept more data calls even on queue. • The new voice and handoff call queue size was decremented taking in consideration that users will wait for a new and hand off call only for a small period of time. • The data threshold was decreased and compensated by the size of the data queue. This leaves more channels for the new voice and handoff calls.