For frequency range that is appropriate for ISL, look at the ITU website. It provides you the complete list of frquencies that are legally OK for ISL.

You can contact the CRA(sazemane tanzim mogharart in seyd khandan) and ASK THEM FOR THE NATIONAL TABLE OF FREQUENCY.

The link budget is not that much difficult. There is no any obstacle around your satellites,  so straight forward ferris formula provides you a good suggestion.

Regards

Mohammad

You can contact an Egyptian expert in the field ( LEO satellite network design), "Prof. Mohamed zahran", his email :

[email protected]

To begin, you'll also need to state how many planes, what the separation of those planes will be and how many satellites are in each plane.

Typically, purpose built communications between satellites is colloquially called "Crosslink". As this is outside the atmosphere your only limiting factors are: 1) Free Space Path Loss 2) Inter-spacecraft network knowledge; how aware does each satellite have to be about where it is in the constellation 3) pointing and directionality of your crosslink. 4) How much money you have to get all this done? 5) ITU available frequencies.

It can take up to 4 years to get the okay from ITU to use a given frequency. Not including the orbital slot. No, I have not filed ITU paperwork myself. The U of M is still building and iterating on its nanosatellite communications boards.

The software package you're looking for is called the Systems Tool Kit (STK) from Analytical Graphics Inc. (AGI)

With it you can model the orbits, the figure of merit for coverage over an area and the link budget. Optimising the orbits using the Walker tool is a non-trival process. They do have a tools called Analyzer and Optimizer that streamline the process. But they aren't free. You'll need some fun justification to your department for those costs. 

http://www.agi.com/products/stk/

You can apply to get and educational licence here:

http://www.agi.com/resources/educational-alliance-program/

They also have excellent training guides:

http://www.agi.com/training/

http://www.agi.com/training/training-materials.aspx

The alternative software solution for you is called FreeFlyer from a.i. solutions.

http://www.ai-solutions.com/productsservices/freeflyer/overview.aspx

So far I haven't had any experience with FreeFlyer. I'd love to give it a try to see how and why it differs from STK.

Be aware that currently, satellite systems technology is often under ITARS restriction from the U.S. and as such your institution may not have access to all of the available features.

Here's a random ITU link for the Space Services Department

http://www.itu.int/en/ITU-R/space/Pages/default.aspx

You've got a great deal of study ahead of you. The learning curve is steep. 

http://www.agi.com/products/stk/

http://www.agi.com/resources/educational-alliance-program/

http://www.agi.com/training/

http://www.agi.com/training/training-materials.aspx

http://www.ai-solutions.com/productsservices/freeflyer/overview.aspx

http://www.itu.int/en/ITU-R/space/Pages/default.aspx

thanks Mr Greg Linton.

i propose four circular planes at altitude 600 Km and three satellites in each plane.i use the stk to simulate this constellation.there is no intra plane ISL but some times inter plane ISLs  has occured.

i need some paper that simulate the cross link and simply explain it.please give me some papers if you have.

thanks

Dear ali

I may be able to help you specifically in LEO constellation designs (Geometry of satellites) which was an extensive research I experienced but the satellites inter link. You can contact me  if you think it can help.

the bests

For Your Information:

I forgot to include anything about the International Traffic in Arms Regulations (ITARS) for those looking at space systems technologies out of the United States.

The following website is directed towards those companies already in the US but its a handy reference for everybody dealing with US related space issues.

http://www.space.commerce.gov/regulations/satellite-export-control-regulations/

This has actually had a positive impact on other countries, forcing them to develop a local capability or go to the EU for business/tech.