1	Enhancing SWAN QoS Model By Adopting Destination-Based Regulation (ESWAN)
2	Agenda Ad-Hoc QoS Independent Models SWAN Building Blocks SWAN Dynamic Regulation Issues ESWAN Basic Terms Observations On SWAN Model ESWAN Destination-Based Regulation Evaluation of ESWAN Conclusion
3	Ad-Hoc QoS Independent Models FQMM (IntServ + DiffServ) dQoS (Fair Dynamic Bandwidth Percentages) INSIGNIA (Stat-full Model) SWAN Stateless AIMD Pragmatic Conservative Expectation of Bandwidth No Resource Allocation Distributed Soft QoS Guarantees E2E RT-Delays ??? Effective BW ???
4	SWAN Building Blocks Admission Controller Classifier Shaper Rate Controller
5	SWAN Admission Controller (AC) Conservative look at BW availability. Use MIN BW available between SRC/DST. Slack of BW used by BE. Use of probe req. reply. Admission provides soft guarantees only. Intermediate nodes do not allocate resources.
6	SWAN Packet Classifier Simply forwards unmarked packets to the Shaper Forward marked packets to the MAC layer
7	SWAN Rate Controller (RC) Follows conservative AIMD approach. Limit throughput to the knee of AIMD chart. Relies on information from MAC layer (packet delay).
8	SWAN Dynamic Regulation Issues Congestion Due to Mobility
9	SWAN Source-Based Regulation Congested node must mark all passing RT packets with CE. Destination nodes inform source nodes with the congestion via QoS reporting mechanism. Source nodes slows down transmission rates. If new rate is unsatisfactory, source nodes re-establish the QoS flow. Fast recovery, aggressive and disruptive to many QoS flows.
10	SWAN Network-Based Regulation Congested node selects only subset of passing RT-flows (victim flows). Same consequences as in Source-Based If congestion is not resolved in time T, select new (victim flows). Victim flows are selected randomly. Slower recovery, less aggressive to RT-flows.
11	ESWAN Basic Terms Define MAPD (Max Acceptable Packet Delay) Define Effective BW = BW without expired packets. Define Effective BW Ratio Define Limited and High QoS Define Effective Delay Ratio
12	Observations On SWAN Model About 10% of RT-packets arrive expired. No parameters to measure flow QoS. No mechanism designed to respond to degraded QoS. Expired BW consumes network resources.
13	ESWAN Destination-Based Regulation Preemptive Behavior Performed by DST node on flows experiencing Limited QoS (no congestion). Limited QoS condition is triggered when (b < b_L)_T. DST node issues regulate message to SRC node. SRC node performs re-initiate procedure to locate new (better) route. Preemptive behavior is a preventative measure. Preemptive behavior maintains QoS levels.
14	ESWAN Destination-Based Regulation Recovery Behavior Congested node marks all RT-packets with CE until node realizes sufficient decrease in arriving BW. DST nodes having (d > d₁) will issue regulate message. Other DST nodes wait for time T. If packets keep arriving with CE, nodes having (d > d₂) will regulate. After another time T, if packets keep arriving with CE, nodes having (d > d₃) will regulate. Values (d_i) are network constants, and (d_i > d_i+1).
15	Evaluation of ESWAN 1 Preemptive behavior limited amount of expired BW in ESWAN compared to SWAN. Recovery behavior caused smoother recovery from congestion in ESWAN compared to SWAN.
16	Evaluation of ESWAN 2 Preemptive behavior caused limited effect on BE traffic. Recovery behavior caused a much less congested node in ESWAN compared to SWAN. The recovery is smoother in ESWAN.
17	Evaluation of ESWAN 3 The delay chart of RT-packets in ESWAN shows less congested packets and fewer expired. Cumulative RT-packet delay % in ESWAN shows about 1.2% only of delivered packets are unusable.
18	Evaluation of ESWAN 4 Higher EBR in ESWAN due to preemptive behavior. Lower EDR in ESWAN due to recovery behavior. Better NW utilization in ESWAN.
19	Conclusion Preemptive behavior decreases chances of congestion. ESWAN facilitates a way to upgrade provided services. Gradual recovery less disrupting to RT-flows. Shaping Rate T is empirical value (2 sec). MAPD is a flow specific value (known to DST). EBR (b) & EDR (d) are important QoS measures. Larger ad-hoc NW need the MAPD to limit expired BW. Future investigation on the effect of imbalanced load bet. RT and BE traffic in SWAN enabled ad-hoc NW.
20	Questions & Remarks