An investigation into dynamic TLPs for smartphone communication: To facilitate timed response in way finding for vision impaired people

A reliable, high speed and efficient data transfer method is a very important factor in real time Way-finding systems since it requires information with very low latency to discover paths, avoid dangerous situations, identified changes in existing maps and alternative routes. This research will develop models and methods to facilitate bounded timing with minimal latency for way-finding application for vision impaired people. As a result of analyzing the requirements for Way-finding applications, it was noted that some typical behaviours involve relatively small amount of data transfer through networks. Existing Transport Layer Protocols (TLP) are not ideal for providing such requirements. This research investigates existing TLPs and proposes modifications / extensions to facilitate demands in Way-finding applications and will implement the Dynamic TLP to incorporate both reliable data transfers with high efficiency as well as frequent data transfers which do not require reliability

TCP over CDMA2000 Networks: A Cross-Layer Measurement Study

Modern cellular channels in 3G networks incorporate sophisticated power control and dynamic rate adaptation which can have significant impact on adaptive transport layer protocols, such as TCP. Though there exists studies that have evaluated the performance of TCP over such networks, they are based solely on observations at the transport layer and hence have no visibility into the impact of lower layer dynamics, which are a key characteristic of these networks. In this work, we present a detailed characterization of TCP behavior based on cross-layer measurement of transport layer, as well as RF and MAC layer parameters. In particular, through a series of active TCP/UDP experiments and measurement of the relevant variables at all three layers, we characterize both, the wireless scheduler and the radio link protocol in a commercial CDMA2000 network and assess their impact on TCP dynamics. Somewhat surprisingly, our findings indicate that the wireless scheduler is mostly insensitive to channel quality and sector load over short timescales and is mainly affected by the transport layer data rate. Furthermore, with the help of a robust correlation measure, Normalized Mutual Information, we were able to quantify the impact of the wireless scheduler and the radio link protocol on various TCP parameters such as the round trip time, throughput and packet loss rate

Web browsing optimization over 2.5G and 3G: end-to-end mechanisms vs. usage of performance enhancing proxies

Published version on Wiley's platform: https://onlinelibrary.wiley.com/doi/abs/10.1002/wcm.4562.5 Generation (2.5G) and Third Generation (3G) cellular wireless networks allow mobile Internet access withbearers specifically designed for data communications. However, Internet protocols under-utilize wireless widearea network (WWAN) link resources, mainly due to large round trip times (RTTs) and request–reply protocolpatterns. Web browsing is a popular service that suffers significant performance degradation over 2.5G and 3G. Inthis paper, we review and compare the two main approaches for improving web browsing performance over wirelesslinks: (i) using adequate end-to-end parameters and mechanisms and (ii) interposing a performance enhancingproxy (PEP) between the wireless and wired parts. We conclude that PEPs are currently the only feasible way forsignificantly optimizing web browsing behavior over 2.5G and 3G. In addition, we evaluate the two main currentcommercial PEPs over live general packet radio service (GPRS) and universal mobile telecommunications system(UMTS) networks. The results show that PEPs can lead to near-ideal web browsing performance in certain scenarios.Postprint (published version

Comparison of User Traffic Characteristics on Mobile-Access versus Fixed-Access Networks

We compare Web traffic characteristics of mobile- versus fixed-access end-hosts, where herein the term "mobile" refers to access via cell towers, using for example the 3G/UMTS standard, and the term "fixed" includes Wi-Fi access. It is well-known that connection speeds are in general slower over mobile-access networks, and also that often there is higher packet loss. We were curious whether this leads mobile-access users to have smaller connections. We examined the distribution of the number of bytes-per-connection, and packet loss from a sampling of logs from servers of Akamai Technologies. We obtained 149 million connections, across 57 countries. The mean bytes-per-connection was typically larger for fixed-access: for two-thirds of the countries, it was at least one-third larger. Regarding distributions, we found that the difference between the bytes-per-connection for mobile- versus fixed-access, as well as the packet loss, was statistically significant for each of the countries; however the visual difference in plots is typically small. For some countries, mobile-access had the larger connections. As expected, mobile-access often had higher loss than fixed-access, but the reverse pertained for some countries. Typically packet loss increased during the busy period of the day, when mobile-access had a larger increase. Comparing our results from 2010 to those from 2009 of the same time period, we found that connections have become a bit smaller

Automated Inference System for End-To-End Diagnosis of Network Performance Issues in Client-Terminal Devices

Traditional network diagnosis methods of Client-Terminal Device (CTD) problems tend to be laborintensive, time consuming, and contribute to increased customer dissatisfaction. In this paper, we propose an automated solution for rapidly diagnose the root causes of network performance issues in CTD. Based on a new intelligent inference technique, we create the Intelligent Automated Client Diagnostic (IACD) system, which only relies on collection of Transmission Control Protocol (TCP) packet traces. Using soft-margin Support Vector Machine (SVM) classifiers, the system (i) distinguishes link problems from client problems and (ii) identifies characteristics unique to the specific fault to report the root cause. The modular design of the system enables support for new access link and fault types. Experimental evaluation demonstrated the capability of the IACD system to distinguish between faulty and healthy links and to diagnose the client faults with 98% accuracy. The system can perform fault diagnosis independent of the user's specific TCP implementation, enabling diagnosis of diverse range of client devicesComment: arXiv admin note: substantial text overlap with arXiv:1207.356

TCP over CDMA2000 Networks: A Cross-Layer Measurement Study

Modern cellular channels in 3G networks incorporate sophisticated power control and dynamic rate adaptation which can have a significant impact on adaptive transport layer protocols, such as TCP. Though there exists studies that have evaluated the performance of TCP over such networks, they are based solely on observations at the transport layer and hence have no visibility into the impact of lower layer dynamics, which are a key characteristic of these networks. In this work, we present a detailed characterization of TCP behavior based on cross-layer measurement of transport, as well as RF and MAC layer parameters. In particular, through a series of active TCP/UDP experiments and measurement of the relevant variables at all three layers, we characterize both, the wireless scheduler in a commercial CDMA2000 network and its impact on TCP dynamics. Somewhat surprisingly, our findings indicate that the wireless scheduler is mostly insensitive to channel quality and sector load over short timescales and is mainly affected by the transport layer data rate. Furthermore, we empirically demonstrate the impact of the wireless scheduler on various TCP parameters such as the round trip time, throughput and packet loss rate

Mobile Internet Usage - Network Traffic Measurements

Perustavanlaatuisia muutoksia on tapahtumassa tietoliikennetoimialalla kun Internet ja mobiili konvergoituvat. Matkapuhelimet ovat kehittymässä multimediatietokoneiksi ja kannettavat tietokoneet muuttuvat pienemmiksi ja sisältävät kasvavissa määrin liitettävyyden matkapuhelinverkkoon. Kun samaan aikaan mobiililaajakaistojen hinnat ovat laskeneet ja tarjotut kaistannopeudet kasvaneet, mobiilin Internetin käyttö on lisääntynyt nopeasti viimeisten parin vuoden aikana. Uusia tulonlähteitä etsiessä teollisuuden eri sidosryhmät ovat kiinnostuneita mittauksista jotka voivat auttaa ymmärtämään mobiilin Internetin käyttöä. Tämä diplomityö keskittyy mobiiliverkon liikennemittauksiin ja niiden soveltuvuuden tutkimiseen markkinatiedon tuottamisessa eri sidosryhmille. Työssä analysoidaan suomalaisissa mobiiliverkoissa tehtyjä liikennemittauksia ja tuotetaan statistiikkaa mobiilin Internetin käytöstä. Lisäksi nykyisen mittausjärjestelyn ominaisuuksia analysoidaan, mahdolliset mittausten kehittämisalueet luokitellaan ja suosituksia esitetään mittausten kehittämiseksi. Statistiikat Suomen mobiilii-Internetin käytöstä osoittivat että tietokoneet generoivat suurimman osan Suomen liikennevolyymistä, kun taas matkapuhelinten tuottaman liikenteen osuus on alle prosentti. Symbian-käyttöjärjestelmä dominoi matkapuhelinten käyttöä joka on web-orientoitunutta. Muitakin web-liikenteen luokkia kuin web-selailua, kuten email- ja muuta synkronointiliikennettä, huomattiin käytettävän matkapuhelimilla. Perinteiset kotimaiset mediatalot, sosiaalisen median sivustot ja Nokia ovat suosituimpien web-sisällöntuottajien joukossa. Koska eri mittauspisteet mobiiliverkossa tuottavat eri tarkkuustason tietoa, täytyy mittausprosessiin liittyvät valinnat tehdä mittauksen tavoitteiden mukaan. Jos kehittynyt analyysi on tarpeen, mittausten olisi suositeltavaa suoritettavan pisteessä jossa käyttäjien tunnistaminen on mahdollista, kun taas pelkästä IP-liikenteestä saatavat tulokset ovat riittäviä yleisempään markkinan kuvaamiseen. Mobiilioperaattorin kannalta yhtäjaksoiset ja automatisoidut mittaukset mahdollistaisivat tulosten hyväksikäyttämisen useissa eri yrityksen toiminnoissa. Yleisesti liikennemittausten mahdollisuudet ovat laajat, mutta toisaalta täyden hyödyn saavuttamiseksi resurssivaateet saattavat olla suuria. Liikennemittaukset voivat kuitenkin tuottaa tietoa ja tukea operaattoreita päätöksenteossa ja liiketoiminnan kehittämisessä.Fundamental transformations are taking place in the telecommunication domain as the Internet and mobile industries are converging. Mobile phones are developing into multimedia computers and laptops are getting smaller with cellular connectivity, increasing the amount of mobile Internet capable devices. Furthermore, as mobile broadband prices have decreased and offered bandwidths increased, also the usage of mobile Internet has been increasing rapidly during the past couple of years. In search for new revenue sources, various industry stakeholders are interested in measurements that can help understanding the mobile Internet usage patterns. This thesis focuses on mobile network traffic measurements and studies their applicability for providing market understanding for the different stakeholders. First, measurements from operational Finnish mobile networks are analyzed to provide factual statistics on the usage patterns of the Finnish market. Second, the properties of the existing measurement organization are analyzed, possible measurement design and development areas are classified, and recommendations are provided for further development of the measurements. The factual statistics showed that most of the Finnish mobile Internet usage traffic volume is generated by computers, whereas the share of mobile handset generated traffic is less than one percent. Symbian operating system dominates the web oriented mobile handset usage. Traditional Finnish media houses, social media sites, and Nokia are among the most popular content providers for web usage. In addition, also other web traffic classes than web browsing, such as email and synchronization, were observed to be used by mobile handsets. As different measurement points in a mobile network provide different data granularity, the choices related to the measurement have to be made according to the objectives of the measurement. If advanced analysis is needed, the measurements are recommended to be conducted at a point in the mobile network where user identification is possible, whereas total traffic level patterns from IP traffic are adequate for general market description. From a mobile operator viewpoint, automated and continuous data collection and analysis could enable utilization of the results in multiple corporate functions. In general, the possibilities of traffic measurements are vast. On the other hand, they may require a lot of resources to succeed in their full potential. Nevertheless, mobile network traffic measurements can provide intelligence and support for operators in their decision making and business development