Bits And Blocks

lad12

Consider sending data in blocks of a 1000 bit.The error rate is 1 in 1000.

A) If the errors are randomly distributed: If we send 500 blocks how many blocks do we expect to contain an error?
If errors come in bursts of 500:If we send 500 blocks, how many blocks do we expect to contain an error?

Anybody able to answer the above questions?I'm lost


I'm thinking (A) is .005?

Not sure what B is at all.

Chalk

im guessing that if
1 block = 1000 bits and
1 error comes for every 1000 bits
then
1 block = 1 error
so 500 blocks = 500 errors

if the error rate is
1 error per 1000 blocks
then errors for 500 blocks = .5 blocks [the same as the first answer but all at once- expalins b]


if you use my answer above with part b then half of one block will have an error

Capt'n Midnight

lad12 wrote:

Consider sending data in blocks of a 1000 bit.The error rate is 1 in 1000.

A) If the errors are randomly distributed: If we send 500 blocks how many blocks do we expect to contain an error?
If errors come in bursts of 500:If we send 500 blocks, how many blocks do we expect to contain an error?

Anybody able to answer the above questions?I'm lost


I'm thinking (A) is .005?

Not sure what B is at all.

more a maths question on probablility than anything else and this ain't the Answer your homework for you forum.

A / - the answer is NOT 100% - anyone who says different does not have a good understanding of the normal distribution. Hint: if this were true setting the MCP to 998 would reduce packet loss to a fraction of 1%

B / Hint: if the error starts in bits 0 to 499 then the error will be contained in one block, if the error occurs in bits 499 to 999 then the error will occur in two blocks.

Also the block CAN'T contain 1000 bits of data - you have to add in overhead for addresses, handshaking etc.(otherwise you aren't networking) Also unless you are using UDP or similar there will be blocks retransmitted so and they and the ACK packets could have errors too.

C / Assume the blocks are being transmitted with a FEC of 2/3 (cf. satellite broadcasting) how many blocks are now lost ???

lad12

more a maths question on probablility than anything else and this ain't the Answer your homework for you forum.

Its not Homework