Almudena Díaz

Mobile Application Profiling for Connected Mobile Devices

The SymPA (Symbian protocol analyzer) tool correlates traffic information, radio-access-technology measurements, and location data to help developers evaluate mobile applications in the field.

Field measurements of mobile services with Android smartphones

The proliferation of mobile Internet services for smartphones makes it more necessary than ever to use measurement tools in mobile devices to monitor their connectivity performance. In this paper we introduce TestelDroid, a software tool for Android devices which provides advanced monitoring functionalities for analyzing multimedia services and applications specifically designed for smartphones. The beneficiaries of this tool are mobile operators, service providers and mobile developers, as TestelDroid offers a unified and independent methodology to analyze performance parameters from the application level, taking into account underlying issues.

Experimental analysis of peer-to-peer streaming in cellular networks

In this paper, we study the adequacy of applying peer-to- peer techniques to mobile networks by conducting a series of experiments using smart phones as peers. We measure important parameters, such as jitter and packet losses, in static and dynamic scenarios, focusing on a video streaming service. Finally, based on the results obtained, we discuss the feasibility of these applications.

Obtaining More Realistic Cross-Layer QoS Measurements: A VoIP over LTE Use Case

We introduce a real-time experimentation testbed in this paper which enables more realistic analysis of quality of service (QoS) in LTE networks. This testbed is envisioned for the improvement of QoS and quality of experience (QoE) through the experimentation with real devices, services, and radio configurations. Radio configurations suggested in the literature typically arise from simulations; the testbed provides a real and controlled testing environment where such configurations can be validated. The added value of this testbed goes a long way not only in the provision of more realistic results but also in the provision of QoS and QoE cross-layer measurements through the correlation of information collected at different layers: from service and IP levels to radio and protocol parameters. Analyzing the interlayer dependencies will allow us to identify optimal settings for the radio access network and service parameters. This information can be used to suggest new cross-layer optimizations to further improve quality of experience of mobile subscribers. As a use case, we examine VoIP service over LTE, which is currently an open issue.

Evaluating Video Streaming Over GPRS/UMTS Networks: A Practical Case

In this paper, we focus on analyzing video streaming service performance on real networks. We propose a non intrusive methodology based on mobile devices as clients, instead of using them as modems. Our objective is to provide a more realistic test environment using actual mobile devices in real conditions of network load and radio propagation while taking into account the intrinsic mobility of mobile subscribers. This solution allows us to follow the end to end performance even when handover between different access technologies is performed. Using this methodology we carry out a study of video streaming behavior over GPRS and UMTS networks. Outstanding results related with delays, jitter, lost packets and sequence errors have been obtained. Also other conclusions about video quality, such as PSNR, have been achieved. Moreover, we analyze the impact of mobility issues such as handover or cell reselection.

Customer-centric measurements on mobile phones

The improved processing power and battery life of mobile devices, as well as the near ubiquitous coverage of wireless data communication networks allow mobile users to use information services in a similar way to desktop users. People not only demand access to existing Internet services from their mobile devices, but also to have available new services specifically designed for mobile environments. In this scenario user centered measurements are decisive in order to adjust networking performance to the experience of mobile users. In this paper we illustrate how existing mobile devices can be used to monitor the performance of mobile Internet services over cellular networks.

Test environment for QoS testing of VoIP over LTE

This application track paper describes an experimental test setup composed to verify the communication performance of internet applications over LTE (Long Term Evolution) networks.

Obtaining Models for Realistic Mobile Network Simulations using Real Traces

Field tests are vital for characterizing mobile networks and applications under real conditions, but may be too costly. Simulations are an alternative for performing this kind of analysis, but may yield results that are too synthetic. In this paper we present a methodology for obtaining more sophisticated and realistic simulations, based on the use of traffic traces from field tests on live networks and an objective-driven simulation approach for parameter tuning. We use this approach to automatically refine parameterized mathematical jitter models, which can be used in network simulations to replicate communication issues presented in wireless networks.

Mobile application profiling with TestelDroid

This demonstration shows a methodology to collect and analyze key performance indicators (KPI) directly from real devices running commercial mobile applications. The main objective of this methodology is to provide a complete multi-layer understanding of the performance of mobile applications and services from the user level, to the radio access through all the stack protocols.

x-AppMonitor μAgent: a tool for QoS measurements in cellular networks

Design, optimization and assurance of GSM and 3G networks are becoming increasingly costly as a consequence of factors such as the high numbers of subscribers, the new and complex traffic patterns and the coexistence of different radio access technologies. One interesting indicator of network performance in a particular area is the quality of service perceived by the final user for specific services. This user perception is gaining importance with regard to services like short messaging or IP-based applications. In this scenario, traditional measurement tools employed by operators could be replaced by the new mobile phones, because they can be used as an environment where measurements can be done directly. This paper reports our experiences developing x-AppMonitor muAgent, a network performance monitoring tool which is executed in off-the-shelf mobile terminals and measures quality of service perceived by users. Practical results will be provided.