mwang@watmath.UUCP (mwang) (02/21/84)
_D_E_P_A_R_T_M_E_N_T _O_F _C_O_M_P_U_T_E_R _S_C_I_E_N_C_E
_U_N_I_V_E_R_S_I_T_Y _O_F _W_A_T_E_R_L_O_O
_S_E_M_I_N_A_R _A_C_T_I_V_I_T_I_E_S
_S_Y_S_T_E_M_S _S_E_M_I_N_A_R
- Friday, March 2, 1984.
Dr. M. Molle of the University of Toronto will speak on
``Virtual Time CSMA: Why Two Clocks are Better than
One.''
TIME: 2:30 PM (Please Note)
ROOM: MC 5158
ABSTRACT
Carrier sense multiple access (CSMA) algorithms are
distributed algorithms used in local area networks to
serialize the transmission of messages over a shared
broadcast communications channel. A new CSMA algorithm
called virtual time CSMA is described and analyzed.
Unlike other CSMA algorithms, the operation of virtual
time CSMA reduces to the ideal case in the zero propa-
gation time limit: a work-conserving, first-come
first-served M/G/1 queueing system. This observation
suggests a technique for constructing simple closed-
form bounds for the mean message delay. This technique
is of independent interest because of its applicability
to certain `sliding window' tree algorithms. Comparis-
ons between simulation and analysis show remarkably
good agreement.
February 21, 1984