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The Uncertainty of Decisions in Measurement Based Admission Control. Thesis for the degree of Philosophia Doctor. Anne Nevin Centre for Quantifiable Quality of Service in Communication Systems (Q2S). Presentation Outline: Introduction and thesis contribution
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The Uncertainty of Decisions in Measurement Based Admission Control Thesis for the degree of Philosophia Doctor Anne Nevin Centre for Quantifiable Quality of Service in Communication Systems (Q2S)
Presentation Outline: • Introduction and thesis contribution • Homogeneous flows, probability of false acceptance and provisioning • Flow dynamics and performance measures • Multiple arrivals within a measurement window, a simulation study • Non homogeneous flows and the Similarflow concept • Conclusion
New application enables new ways of using the internet but also adds challenges…
A key requirement of Real-time applications is short network delay
The packets must be ’clocked’ at the same rate on both sides Constant network delay Well-ordered sequence of packets
When demand exceeds the capacity queues build up in routers delay is no longer constant Well-ordered sequence of packets
When demand exceeds the capacity queues build up in routers Queue of packets Packets received with jitter Varying network delay
When demand exceeds the capacity queues build up in routers Queue of packets Varying network delay jitter buffer
Packets that do not make it on time will be discarded Queue of packets too late Varying network delay jitter buffer
Admission control to prevent network congestion Queue of packets Varying network delay jitter buffer
Internet flows representing real-time applications and a singel network link with limited capacity The exhibition venue
The exhibition venue has limited space and it is popular Venue passes are expensive
Exhibition room with capacity c Exhibition Venue Admission Control
Exhibition room with capacity c Exhibition Venue YES Admission Control
Exhibition room with capacity c Exhibition Venue Admission Control
Exhibition room with capacity c Exhibition Venue Admission Control
Exhibition room with capacity c Exhibition Venue Admission Control
Exhibition room with capacity c Exhibition Venue Admission Control
Exhibition room with capacity c Exhibition Venue Admission Control
Exhibition room with capacity c Exhibition Venue Admission Control
Exhibition room with capacity c Exhibition Venue NO Admission Control
Exhibition room with capacity c Exhibition Venue NO Admission Control
Exhibition Venue Admission Control
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
The number of people at the venue will vary with time Exhibition Venue N (t) only one pass sold Admission Control t time in system
One person represents 1 Mbps while in the exhibition room Aggregate rate R (t) only one pass sold Admission Control 1 Mbps t time in system
Every person represents 1 Mbps while in the exhibition room Aggregate rate n passes sold Admission Control R(t) t
Every person represents 1 Mbps while in the exhibition room c = 1000Mbps Admission Control c R(t) t
How many passes can you sell? c = 1000Mbps Admission Control c R(t) t
Probability that all passholders are at the expo simultaneously is very very very small Sell more than 1000 passes
Measurement Based Admission Control, MBAC Observation estimate: ucis themaximumaverage rate MBAC 1000 Admit if: < uc R(t) window Tuning = u, 0<u <1 t
But how accurate are these estimates? Observation estimate: ucis themaximumaverage rate MBAC 1000 Admit if: < uc R(t) window t
How long do we need to observe to judge the accuracy of the measurement? Observation estimate: ucis themaximumaverage rate MBAC 1000 Admit if: < uc R(t) window t
There is an uncertainty in the admission decision Admit too many Not enough