TY - GEN
T1 - Delay bounds for packetizing time-varying fluid policies with speedup and lookahead in single server systems
AU - Yim, Raymond
AU - Rosenblum, Michael
AU - Tarokh, Vahid
PY - 2005/10/7
Y1 - 2005/10/7
N2 - We consider an online, processor sharing system with a single server in a packet-switched network where the processor multiplexes packets from multiple input ports onto the same output link. Under a fluid model, in which incoming data is treated as infinitely divisible, the multiplexer allocates its output capacity to serve fractions of packets from all input ports simultaneously (which we call a fluid policy). However, due to the packet nature of the network traffic, a multiplexer scheduler must approximate this fluid policy by a schedule in which only whole packets are sent (which we call a packetized policy). We assume that at each time instant, the aggregate service rate demanded by a fluid policy is no greater than the output link capacity. Then, for a single server with N input ports, and a scheduler using speedup s of at least 2 and a lookahead window of L ≥ 0 time steps, we prove bounds on worst-case maximum additional delay D. In particular, we show that (⌈Ne-s⌉ - L - 2)+ ≤ D ≤ min {(⌈Ne1-s⌉ - L)+, ⌈Ne -s⌉}. In the case when no lookahead is used (L = 0), a tighter bound can be obtained: (⌈Ne-s⌉ - 2)+ ≤ D ≤ ⌈Ne-s⌉.
AB - We consider an online, processor sharing system with a single server in a packet-switched network where the processor multiplexes packets from multiple input ports onto the same output link. Under a fluid model, in which incoming data is treated as infinitely divisible, the multiplexer allocates its output capacity to serve fractions of packets from all input ports simultaneously (which we call a fluid policy). However, due to the packet nature of the network traffic, a multiplexer scheduler must approximate this fluid policy by a schedule in which only whole packets are sent (which we call a packetized policy). We assume that at each time instant, the aggregate service rate demanded by a fluid policy is no greater than the output link capacity. Then, for a single server with N input ports, and a scheduler using speedup s of at least 2 and a lookahead window of L ≥ 0 time steps, we prove bounds on worst-case maximum additional delay D. In particular, we show that (⌈Ne-s⌉ - L - 2)+ ≤ D ≤ min {(⌈Ne1-s⌉ - L)+, ⌈Ne -s⌉}. In the case when no lookahead is used (L = 0), a tighter bound can be obtained: (⌈Ne-s⌉ - 2)+ ≤ D ≤ ⌈Ne-s⌉.
KW - Packet Networks
KW - Packetizing Algorithm.
KW - Switching and Scheduling
KW - Time-Varying Fluid Policy
UR - http://www.scopus.com/inward/record.url?scp=25644459345&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=25644459345&partnerID=8YFLogxK
U2 - 10.1109/INFCOM.2005.1498543
DO - 10.1109/INFCOM.2005.1498543
M3 - Conference contribution
AN - SCOPUS:25644459345
SN - 0780389689
T3 - Proceedings - IEEE INFOCOM
SP - 2590
EP - 2601
BT - Proceedings - IEEE INFOCOM 2005. The Conference on Computer Communications - 24th Annual Joint Conference of the IEEE Computer and Communications Societies
A2 - Makki, K.
A2 - Knightly, E.
T2 - IEEE INFOCOM 2005
Y2 - 13 March 2005 through 17 March 2005
ER -