Protocol Stack

http://en.wikipedia.org/wiki/Protocol_stack

- Dejan

http://en.wikipedia.org/wiki/Protocol_stack

- Dejan

Wikipedia says:
"A protocol stack is a particular software implementation of a computer networking protocol suite."

Wikipedia further defines:
"Computer networking is the scientific and engineering discipline concerned with communication between computer systems."


So the term "computer networking" may be a bit misleading here: protocol stacks are certainly not restricted to computer networking - a protocol stacks is any software implementation of any communications protocol.

eg, your mobile phone contains a GSM (or whatever) protocol stack; telephone networks make extensive use of protocol stacks, etc, etc,...

This is the point where we quibble about whether or not a cell phone or telco switch is a "computer"...

(I think so, at least for this purpose. But of course you can counter-quibble that there exist protocols that don't involve computers -- say, Morse code, or semaphore, and the address that sends the telegram on beyond the receiving telegraph station; or proper etiquette when "calling CQ" or "breaking" into a CB channel.)

"a protocol stacks is any software implementation of any communications protocol."
,so can i say that it is a driver or firmware.

if i have to implement protocol stack for RF(433MHZ Transciever),how should i start about it?

Regards.

First -- can you buy the code you need? There are companies that do nothing but sell code for popular protocol stacks.

Really common protocols (say, TCP/IP) you can often get for free. Consider whether the GPL is an issue for your project.

If you have to write it from scratch, then you're going to need the specifications for the protocols in question. (I don't think you've yet mentioned exactly which ones you need.) Since standards are often written in a fairly hard-to-understand manner, you might also want a book that describes the protocols in question.

Protocols generally are defined in layers, which tend to make natural points for breaking up your code into modules and functions. Implementations for big iron often use threads or processes for each layer, but I think for an 8051 it would be better to keep it simple, and just make function calls.

How could i generate the specifications, i only have two 8051 based boards and two RF(433MHz) Trancievers?

All the information what i have is that ,i have to communicate 13 nodes(RF Transciever) with a computer for Data acquitation(Collection) and Control.

Regards

Is it confidential or a business secret?

Do you mean to say the protocol is not specified as a requirement, but that you are free to choose any protocol that you like?

Or even that you intend to design your own protocol??

" i only have two 8051 based boards ... i have to communicate 13 nodes"

How do you intend to support 13 nodes with only 2 boards?

Do you mean the 13 nodes are all connected to one board, which aggregates the data and transmits it to the other?
Or what?

Thanks for your immediate resoponse!

Yes ,i have to develop it from scratch.

i can choose any protocol.

at the moment i am experimenting with two boards only(master and node),final design will have ,13 nodes communicating to a single master and then the master will communicate with the host computer and process the accquire data.

Master node is responsible for accquring/communicating data from nodes,while host computer is responsible for processing of data

"i have to develop it from scratch"

Do you mean:

(1). You have chosen an existing protocol specification, and want to implement it from scratch?

(2). You are not using any existing protocol - you want to both design the protocol and implement it yourself from scratch?


Given that this thread started with the question, "what is a protocol stack", I think (1) is somewhat ambitious and (2) is probably out of the question - especially for an RF protocol!

in my case option 2 is the right answer!

"(2). You are not using any existing protocol - you want to both design the protocol and implement it yourself from scratch?"

And, as I said before, given that you needed to ask the question, "what is a protocol stack", I think you are biting off far more than you can chew!

Even integrating a ready-made implementation into your own design is generally a non-trivial task - doing the whole thing from scratch with no prior experience is either extreme self-confidence or sheer folly!

Good luck!

well, based on the sparse information he has provided so far, I think he does NOT need a protocol stack, just a protocol.

Erik