Saeesh,
The IxWLAN will provide you with an excellent tool for testing signal strength, errors, retransmissions, etc. while also emulating up to 128 virtual wireless stations on three independent radios. It does not include a packet sniffer but we can recommend several solutions that will fit with the IxWLAN tool. I would also strongly recommend the IxChariot software package which is the tool-of-choice for generating traffic in wireless test labs. IxChariot is available in a bundled kit with the IxWLAN hardware.
Best regards,
Eric Wenger
Technical Marketing Engineer - Ixia