ANALISIS TINGKAT KINERJA JARINGAN WIRELESS IEEE 802.11N MENGGUNAKAN MIKROTIK

Jaringan wireless merupakan sekumpulan komputer yang saling terhubung antara satu komputer dengan komputer yang lain sehingga menjadi sebuah jaringan komputer. Jaringan ini menggunakan media udara/gelombang untuk mentransmisikan data. Pada suatu jaringan, kecepatan dipengaruhi oleh perangkat yang digunakan oleh user dan perangkat yang menjadi AP, jarak dan faktor ruangan. Pada penelitian ini mencoba melihat kinerja jaringan wireless IEEE 802.11n. Penelitian ini dilakukan halaman rumah dengan menggunakan 4 laptop, 3 sebagai client dan 1 laptop sebagai server dengan 1 router Mikrotik sebagai access point (AP). Pengujian ini dilakukan mencari nilai rata-rata Uplink dan Downlink dari Throughput, Jitter dan Packet Loss dengan pengujian dengan 4 pengujian dengan jarak berbeda-beda, yaitu 5 meter, 10 meter, 15 meter dan campuran menggunakan tool Jperf dengan paket UDP yang telah disesuaikan oleh IEEE 802.11N, waktu selama 50 detik dan bandwidth default. Dari hasil pengujian yang telah dilakukan client dengan jarak 5 meter dari AP memiliki throughput 1 Mbps, jitter 2.536 ms dan packet loss 0%, Sedangkan pada saat jarak 15 dan campuran packet loss mengalami kehilangan paket yang lebih besar yaitu pada data rate 150 mengalami 33.59% kehilangan data dan jarak campuran mengalami 30.56% kehilangan data, sehingga paket yang dikirim tidak sesuai dari data yang sebelumnya. Dari pengujian ini juga bisa dilihat juga perangkat dan ruangan yang memiliki hambatan sangat berpengaruh kualitas sinyal internet tersebut. Kata kunci: server, client, Throughput, AP, Bandwidth, Packet Loss, Jitter, UDP, Jaringan wireless, MikroTik dan Jperf.

Research and Improvement of the Performance of Road Transport Wireless Communication Networks

Global development trends such as the increase in the number of cars, an increased number of smart devices with wireless network connections, and the rapid increase in the amount of transmitted information promote the demand for higher data exchange speed, mobility, and higher level of connectivity. Consequently, data transmission services are also required when users travel by vehicle. As the number of vehicles increases, the problems related to road safety and traffic flow management need to be addressed as well. These problems underline the need for modern, technically, and economically justified communication solutions for Intelligent Transport Systems (ITS). One of the wireless network technologies that can be used for ITS needs, in particular for providing car passengers with access to the data transmission network, is WLAN IEEE 802.11n/ac. The implementation of such WLAN-based automotive wireless access networks requires several issues to be addressed, mainly related to fast-moving objects. In practice, a two-rank wireless network is used, which can provide access to the Internet. Several testbeds of a two-rank road transport communication network using WLAN IEEE 802.11n and LTE technologies were created and studied in the developed Doctoral Thesis. The change in the traffic characteristics of a two-rank communication network was experimentally assessed using LTE hardware from various manufacturers. The performance of such hybrid communication channels was studied depending on the velocity of mobile customers, the number of customers, and the traffic scenarios used. New relationships characterising the performance of the integrated IEEE 802.11n and LTE road transport networks and describing the dependence of network throughput on the velocity of mobile client movement were obtained. A single-rank IEEE 802.11ac technology-based automotive communications testbed has also been developed and studied within the Doctoral Thesis. An improved handover algorithm based on the IEEE 802.11v protocol has been developed and implemented during the research. The relationships describing the performance of such single-rank automotive communication network were theoretically evaluated.

Autotransporta bezvadu sakaru tīklu veiktspējas pētīšana un tās paaugstināšana

Globālās attīstības tendences – automobiļu skaita pieaugums, viedo ierīču ar bezvadu tīkla savienojumu skaita palielināšanās un pārraidāmās informācijas apjoma straujais pieaugums – veicina pieprasījumu pēc lielāka datu apmaiņas ātruma, mobilitātes un augstāka savienojamības līmeņa. Tādējādi tiek pieprasīti datu pārraides pakalpojumi arī tādos gadījumos, kad lietotāji pārvietojas ar autotransportu. Pieaugot automobiļu skaitam, jārisina arī problēmas, kas ir saistītas ar drošību uz ceļiem un transporta plūsmu vadību. Šīs problēmas akcentē nepieciešamību pēc mūsdienīgiem, tehniski un ekonomiski pamatotiem intelektuālo transporta sistēmu (ITS) sakaru risinājumiem. Viena no bezvadu tīklu tehnoloģijām, ko var izmantot ITS, konkrēti – automobiļu pasažieru, vajadzību nodrošināšanai ar piekļuvi datu pārraides tīklam, ir WLAN IEEE 802.11n/ac. Realizējot šādus WLAN bāzētus automobiļu bezvadu sakaru piekļuves tīklus, ir jārisina vairāki jautājumi, kas galvenokārt ir saistīti ar ātri kustīgiem objektiem. Praksē izmantojams ir divrangu bezvadu sakaru tīkls, kas var nodrošināt piekļuvi internetam. Promocijas darbā izveidotas un izpētītas vairākas divrangu autotransporta sakaru tīkla testgultnes, izmantojot WLAN IEEE 802.11n un LTE tehnoloģijas. Eksperimentāli novērtēts, kā mainās datu trafika raksturlielumi divrangu sakaru tīklā, izmantojot dažādu ražotāju LTE aparatūru. Pētīta šādu hibrīdu sakaru kanālu veiktspēja atkarībā no mobilo klientu pārvietošanās ātruma, klientu skaita un izmantotajiem kustības scenārijiem. Iegūtas jaunas integrētu IEEE 802.11n un LTE autotransporta sakaru tīklu veiktspēju raksturojošas likumsakarības, kas apraksta tīkla caurlaidspējas atkarību no mobilā klienta pārvietošanās ātruma. Promocijas darbā izveidota un izpētīta arī vienranga autotransporta sakaru testgultne, kas bāzēta IEEE 802.11ac tehnoloģijā. Pētījumā izstrādāts un realizēts uzlabots IEEE 802.11v standartā bāzēts pārslēgšanās procedūras (angļu val. handover) algoritms. Šādam vienranga automobiļu sakaru tīklam teorētiski novērtētas veiktspēju raksturojošas likumsakarības.

Investigation and Evaluation of IEEE 802.11n WLANs Link Features Performance Under Single Host and Concurrent Communication

For an efficient design of wireless local-area networks (WLANs), the simulation tools are important to accurately estimate the IEEE 802.11n/ac link features for WLANs. However, this true simulation of network behavior is critical in designing high-performance WLANs. Through testing, analysis, and modeling of the proposed scheme repetitively, the design of the WLAN can be enhanced with a small budget before making its practical implementation. Many network simulation tools have been established to give solutions for this request and ns-3 is the most widely used tools among them by the research industry as an open-source network simulator. In this paper, we examine the various link features of the 802.11n WLANs under several conditions. We investigate the effects of 802.11n WLAN modulation and coding schemes (MCSs), 20MHz single channel or 40 MHz bonded channel, guard intervals (GI), frame aggregation, data encoding, number of antennas and their data rate, and link distance features of 802.11n WLAN in ns-3 when only a unique host connects with the access point (AP) and generates data traffic. Besides, the performance for an enterprise scenario proposed by the IEEE 802.11ax study group is evaluated when several hosts are simultaneously creating traffic with their associated APs. The results demonstrate that ns-3 support most of the link features of the 802.11n protocol with significant accuracy.