System model 上浒充通大学 Capacity definition SHANGHAI JIAO TONG UNIVERSITY Per-node Throughput:For a given scheme,we define the per-node throughput as the maximum achievable transmission rate.In t time slots,we assume that there are M(i, packets transmitted from node i to its destination(s).Firstly,the long term per-node throughput is defined as (n)=lim inf M(i,t) t-00 t Afterwards,the per-node throughput of this model for a given scheme is defined by the maximum T(n)satisfying lim Pr((n)T(n)for all i)=1 1-→o0 Per-node Capacity:For a given network,the per-node capacity of it is defined as C(n)=max T (n) where o is a scheme for the network,is the set of all possible schemes,and T(n)is the per-node throughput of scheme o. 16
System model Capacity definition 16 Per-node Throughput: For a given scheme, we define the per-node throughput as the maximum achievable transmission rate. In t time slots, we assume that there are M(i,t) packets transmitted from node i to its destination(s). Firstly, the long term per-node throughput is defined as Afterwards, the per-node throughput of this model for a given scheme is defined by the maximum T(n) satisfying t M i t n t i ( , ) ( ) lim inf → = lim Pr( ( ) ( ) for all ) =1 → n T n i i n Per-node Capacity: For a given network, the per-node capacity of it is defined as where is a scheme for the network, is the set of all possible schemes, and is the per-node throughput of scheme . T (n) C(n) max T (n) =
System model 上浒充通大学 Delay definition SHANGHAI JIAO TONG UNIVERSITY Delay:For a given scheme,assuming that the source sends the packet to the network at time slot fs and the destination receives the packet at time slot ta,the delay is defined as the average value of ts-ta i.e., D(n)=E(t-ta) It should be noted that the queuing delay at source is not considered here,which is the same as in many important works.Moreover,for wireless networks,we assume that the operation time spent in coding/decoding is negligible compared to the transmission time. 17
System model Delay definition 17 Delay: For a given scheme, assuming that the source sends the packet to the network at time slot ts and the destination receives the packet at time slot td , the delay is defined as the average value of ts - td , i.e., It should be noted that the queuing delay at source is not considered here, which is the same as in many important works. Moreover, for wireless networks, we assume that the operation time spent in coding/decoding is negligible compared to the transmission time. ( ) ( ) D n t t = − E s d
Main idea of this paper 上洋充通大 SHANGHAI JIAO TONG UNIVERSITY Restricted mobility model Unicast Capacity,Delay Multicast Capacity,Delay Multicast gain (The capacity and delay gain of multicast comparing with unicast) V More general case (The upper-bound and lower- bound of multicast gain) 18
Main idea of this paper 18 Restricted mobility model Unicast Capacity, Delay Multicast Capacity, Delay Multicast gain (The capacity and delay gain of multicast comparing with unicast) More general case (The upper-bound and lowerbound of multicast gain)
Main contribution of this paper 上浒充通大￥ SHANGHAI JIAO TONG UNIVERSITY Related work Our contribution Throughput upper-bound The same throughput Upper-bound achieving scheme Unicast capacity Unicast Multi-hop transmission Multicast capacity gain scheme[7] Delay Lower-bound Unicast delay The same delay Lower-bound achieving scheme except for a<2 7- 一厂 Throughput upper-bound (Based on a round cut) Multicast capacity I Upper-bound achieving scheme Multicast No related work Multicast Delay gain Delay Lower-bound Multicast delay Lower-bound achieving scheme [7]M.Garetto,E.Leonardi,"Restricted Mobility Improves DelayThroughput Tradeoffs in Mobile Ad Hoc Networks,"in IEEE Transactions on Information Theory,vol.56,no.10,pp.5010-5029,2010. 19
Main contribution of this paper 19 Multi-hop transmission scheme[7] Throughput upper-bound Upper-bound achieving scheme Unicast capacity Delay Lower-bound Lower-bound achieving scheme Unicast delay Throughput upper-bound (Based on a round cut) Upper-bound achieving scheme Delay Lower-bound Lower-bound achieving scheme Multicast capacity Multicast delay No related work Multicast capacity gain Multicast Delay gain The same throughput The same delay except for α<2 Unicast Multicast Related work Our contribution [7] M. Garetto, E. Leonardi, “Restricted Mobility Improves DelayThroughput Tradeoffs in Mobile Ad Hoc Networks,” in IEEE Transactions on Information Theory, vol. 56, no. 10, pp. 5010-5029, 2010
Outline 上浒充通大￥ SHANGHAI JIAO TONG UNIVERSITY ▣Introduction System model and main idea The impact of mobility on capacity for restricted mobility model The capacity of unicast case The capacity of multicast case >The multicast capacity gain The impact of mobility on delay for restricted mobility model Discussion Conclusion and future direction 20
20 Outline ❑ Introduction ❑ System model and main idea ❑ The impact of mobility on capacity for restricted mobility model ➢ The capacity of unicast case ➢ The capacity of multicast case ➢ The multicast capacity gain ❑ The impact of mobility on delay for restricted mobility model ❑ Discussion ❑ Conclusion and future direction