IMPROVEMENT OF CELLULAR PERFORMANCE BY OFFLOADING MOBILE SUBSCRIBERS TO LOCAL XDSL CONNECTIONS

Thomsen, Jesper Graversgaard ; Mandrup, Daniel ; Remlein, Piotr

4. term

Networks and Distributed Systems, Master

2016

2016-06-01

197

Efterspørgslen efter mobildata vokser konstant, men udbygning af mobilnet er dyr og langsom. Dette projekt undersøger en billig måde at aflaste mobilnettet ved at udnytte ledig kapacitet på eksisterende xDSL-forbindelser (fast bredbånd over telefonlinjer). Løsningen gør mobiltrafik mulig via et separat Wi‑Fi-netværk og sigter mod at være enkel at implementere. Arbejdet fokuserer på fire områder: netværksintegritet, Quality of Service (QoS), autentificering og brugeridentifikation. Netværksintegritet: For at beskytte både xDSL‑abonnentens privatliv og mobilbrugernes data oprettes et isoleret Wi‑Fi‑netværk, og der håndhæves stramme firewall‑regler. Sårbarhedsskanninger af prototypen viste ingen tegn på sikkerhedsproblemer. Quality of Service: QoS (prioritering af trafik for at beskytte ydeevnen) er nødvendig for at sikre, at xDSL‑abonnentens betalte tjeneste ikke forringes. Der implementeres flere QoS‑mekanismer, og trafikken for hvert netværk identificeres via portoversættelse, så Telenor kan anvende QoS på deres side for nedstrøms trafik. Målinger viser, at opstrøms QoS ikke altid kan garanteres, når det trådløse medie er overbelastet. Nedstrøms QoS bør i princippet kunne sikres, når QoS anvendes hos Telenor, så længe flaskehalsen er xDSL‑forbindelsen og ikke det trådløse medie. Autentificering og brugeridentifikation: Kun Telenor‑mobilabonnenter skal kunne tilslutte sig det nye Wi‑Fi‑netværk, og danske regler kræver logning af data for hver enkelt bruger. En RADIUS‑server (et standard system til netværkslogind og logning) anvendes til at autentificere brugere og registrere abonnentoplysninger. For at knytte den korrekte trafik til den rette bruger bruges portoversættelse. Forskellige tests er gennemført som et proof‑of‑concept.

Mobile data demand keeps rising, but expanding cellular networks is costly and slow. This project explores a low‑cost way to ease the load by using spare capacity on existing xDSL connections (fixed broadband over telephone lines). The solution makes mobile traffic available via a separate Wi‑Fi network and aims to be simple to deploy. The work addresses four areas: network integrity, Quality of Service (QoS), authentication, and user identification. Network integrity: To protect the privacy of both the xDSL subscriber and mobile users, the system creates an isolated Wi‑Fi network and enforces strict firewall rules. Vulnerability scans of the prototype showed no signs of security issues. Quality of Service: QoS (traffic prioritization to protect performance) is needed to ensure the xDSL subscriber’s paid service is not degraded. Several QoS mechanisms are implemented, and traffic from each network is identified via port translation, allowing Telenor to apply downstream QoS on their side. Measurements show that upload QoS cannot always be guaranteed when the wireless medium is congested. Download QoS should, in principle, be ensured when QoS is applied by Telenor, as long as the bottleneck is the xDSL link and not the wireless medium. Authentication and user identification: Only Telenor mobile subscribers may join the new Wi‑Fi network, and Danish data retention rules require per‑user logging. A RADIUS server (a standard system for network logins and logging) is used to authenticate users and record subscriber information. Port translation is used to associate traffic with the correct user for logging. Various tests were conducted as a proof of concept.

[This abstract was generated with the help of AI]

Cellular ; Hotspot ; Offload ; xDSL ; Technicolor ; Wireless ; Bandwidth ; Performance measurements ; Throughput

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