Hence,W is For exhaustive systems y--2r-”2 m i=o W=R+pW+Y→W= R+Y ax2 (m-p)v 1-p2(1-p)'2(1-p) ·For gated systems =I2r空 m m i=o W-3 2x2(m-p+2)严 1-p) 2(1-p) Weigiang Sun Communication Networks 10Weiqiang Sun Communication Networks Hence, W is 10 • For exhaustive systems • For gated systems   1 0 1 1 2 m i i m Y E Y i V V m           0 1 1 2 m i i m Y E Y i V V m              2 1 2 1 2 1 R Y X m V W R W Y W                         2 2 2 1 2 1 X m V W          