Tehnike višestrukog pristupa mediju po dodijeljenim kanalima

master's thesis

• Title (english): Multiple access techniques with allocated channels
• Author: Adrijan Jakšić
• Mentor: Alen Bažant (mentor)
• Committee member: Alen Bažant (predsjednik povjerenstva)
• Committee member: Branko Mikac (član povjerenstva)
• Committee member: Mirko Sužnjević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2016-07-08, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Computing
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering

Abstract

U lokalnim mrežama, mnogi korisnici dijele prijenosni medij za komunikaciju. Da bi se izbjegli sukobi pristupa prijenosnom mediju, kada dvije različite stanice šalju podatke istovremeno, mogu se koristiti tehnike FDMA, TDMA te tehnike pristupa mediju dodijeljenog po potražnji. Međutim, za praskav promet dolazaka, tehnike slučajnog pristupa mediju su učinkovitije jer medij nije fiksno zauzet. Zbog sudara paketa, mreža s tehnikom pristupa mediju čista ALOHA ima maksimalno prometno opterećenje, odnosno propusnost od oko 18.5%. Kod tehnike slotted ALOHA maksimalna propusnost je povećana za dvostruko do oko 37%. Tehnikom CSMA maksimalna propusnost se dobiva i preko 50%.
Izrazi za određivanje propusnosti te prosječnog kašnjenja prijenosa u lokalnoj mreži koristeći TDMA, FDMA i CDMA su izvedeni. Općenito, prosječno vrijeme prijenosa putem tehnike TDMA je uvijek manje (za broj stanica N > 2) od korištenja tehnika FDMA ili CDMA. Pokazano je da tehnike FDMA i CDMA imaju isto prosječno kašnjenje prijenosa.

Abstract (english)

In local area networks, the transmission channel for communication is often shared by many users. To avoid conflicts of access to the transmission channel, such as two stations transmitting at the same time, FDMA, TDMA, and demand assignment techniques can be used. However, for bursty input traffic, random access techniques have been found to be more efficient because the medium is not fixed assigned. Because of collisions, a pure ALOHA network has a maximum utilization factor of about 18.5%. When slotted ALOHA is considered the maximum throughput is increased to about 37%. With CSMA method, the maximum throughput is over 50%.
Expressions for determining the average transfer delay in local area networks using TDMA, FDMA and CDMA are derived. In general, the average transfer delay using TDMA is always smaller (for number of stations N > 2) than that of using FDMA or CDMA. It is shown that CDMA and FDMA have the same average transfer delay.

• Keywords: računalna mreža; lokalna mreža; propusnost; kašnjenje prijenosa; tehnike višestrukog pristupa; FDMA; TDMA; CDMA
• Keywords (english): computer network; local area network; throughput; transfer delay; multiple access techniques; FDMA; TDMA; CDMA
• Language: croatian
• URN:NBN: urn:nbn:hr:168:241657
• Study programme: Title: Information and Communication Technology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka informacijske i komunikacijske tehnologije (magistar/magistra inženjer/inženjerka informacijske i komunikacijske tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2018-02-06 09:22:52