(30 points) Medium Access Control (Questions) Q1: (25 points) Explain in your own words the evolution from Aloha to CSMA/CD. Explain how they differ and how each newer protocol improves the previous one: describe each one how it works and provide its perforamance, then contrast it with the protocol it improves. Q2: (5 points) What is the purpose of collision detection in CSMA/CD

: Provided below in the explanation section

Explanation:

ALOHA ,CSMA and CSMA/CD are Random access protocol which goes under Multiple entrance protocol.

IN arbitrary or random access protocol no station is relegated any predominance. In wcich each station have equivalent rights over the medium in which they need to transmit information.

Salaam is an irregular access protocol, a framework for getting to the mutual correspondence Networks channel. It was created during the 1970s by Norman Abramson and his partners at the University of Hawaii.

In Aloha, different stations can transmit information simultaneously and can henceforth prompt crash and information being jumbled.

From research we can say that there are two unique renditions of ALOHA:

In the Slotted ALOHA, the hour of getting to the mutual channel is partitioned into discrete intervals called slots.

While for the Pure ALOHA, the stations transmit outlines at whatever point they have information to send.

Opened ALOHA was created to improve the productivity of unadulterated ALOHA as odds of impact in unadulterated ALOHA is exceptionally high.

Still there are a few weaknesses in Aloha i.e, In ALOHA, hubs transmit parcels when they are accessible, without detecting the remote bearer. Therefore, parcels may crash at a beneficiary on the off chance that they are transmitted at the same time.

TO maintain a strategic distance from the above issue there came another protocal CSMA which is called as Carrier Sense Multiple Access (it is an improved type of irregular access convention that previously existed). The name its self proposes that in this the hubs first sense the remote medium before transmitting their information bundles. In the event that the medium is detected occupied, at that point transmissions are postponed else the information bundles are transmited.

After which CSMA/CD (Carrier sense different access with crash location) and CSMA/CA (Carrier sense numerous entrance with impact shirking) are acquainted with further more increment the productivity in impact recognition and impact evasion individually. When a collosion is dectected by CSMA/CD, it retransmits the impacted casings again by halting the transmision when crash recognized. Where as CSMA/CA thoroughly stays away from crash it helps in maintaining a strategic distance from impacts with the assistance of Interframe space(), Contention Window and Acknowledgment

For Q2:-

The prime reason for development from ALOHA to CSMA/CD is that the crash between the data packets.

That is to say CD in CSMA/CD i.e, Collision Detection reason for existing is that, at whatever point a crash occurs in a medium between the parcels it will help in halting the transmission and retransmit the impacted casing again and afterward proceeds with the halted transmission.