COMP362 Assignment 2
1
a) The probability that a packet can reach B is that the packet is successfully
received at every step. Thus the probability is 0
.
8
9
= 0
.
11. It can be seen
that even the probability of every link is relative high, the end to end receive
probability is still low.
b)Assume the probability of every link is
p
. We have
p
9
= 0
.
8 which shows
that
p
= 0
.
97.
2
By applying
Z
i,m
=
d
i
*
c
m
and
Z
*
i,m
=
∑
N
s
=1
Z
S
i,m
, the data sent by sender1
is (

1
,

1
,
1
,
1
,
1
,
1
,

1
,

1
,
1
,
1
,

1
,

1
,

1
,

1
,
1
,
1) and the data sent by
sender2 is(1
,
1
,
1
,

1
,
1
,
1
,

1
,
1
,
1
,
1
,
1
,

1
,
1
,
1
,

1
,
1). The aggregate result
received by receiver is (0
,
0
,
2
,
0
,
2
,
2
,

2
,
0
,
2
,
2
,
0
,

2
,
0
,
0
,
0
,
2). By applying
d
i
=
1
M
∑
M
m
=1
Z
*
i,m
*
c
, we can compute at the receiver that the bits sent by
sender1 is (1
,

1) and sender2 is (1
,
1).
3
Suppose station A and C are transmitting to station B. A and C can not
hear each other’s transmissions. However A’s and C’s transmissions are