Detection and Combining Techniques for Asynchronous Random Access with Time Diversity

Asynchronous random access (RA) protocols are particularly attractive for their simplicity and avoidance of tight synchronization requirements. Recent enhancements have shown that the use of successive interference cancellation (SIC) can largely boost the performance of these schemes. A further step forward in the performance can be attained when diversity combining techniques are applied. In order to enable combining, the detection and association of the packets to their transmitters has to be done prior to decoding. We present a solution to this problem, that articulates into two phases. Non-coherent soft-correlation as well as interference-aware soft-correlation are used for packet detection. We evaluate the detection capabilities of both solutions via numerical simulations. We also evaluate numerically the spectral efficiency achieved by the proposed approach, highlighting its benefits.Comment: 6 pages, 7 figures. Work has been submitted to the 11th International ITG Conference on Systems, Communications and Coding 201

QoE Modelling, Measurement and Prediction: A Review

In mobile computing systems, users can access network services anywhere and anytime using mobile devices such as tablets and smart phones. These devices connect to the Internet via network or telecommunications operators. Users usually have some expectations about the services provided to them by different operators. Users' expectations along with additional factors such as cognitive and behavioural states, cost, and network quality of service (QoS) may determine their quality of experience (QoE). If users are not satisfied with their QoE, they may switch to different providers or may stop using a particular application or service. Thus, QoE measurement and prediction techniques may benefit users in availing personalized services from service providers. On the other hand, it can help service providers to achieve lower user-operator switchover. This paper presents a review of the state-the-art research in the area of QoE modelling, measurement and prediction. In particular, we investigate and discuss the strengths and shortcomings of existing techniques. Finally, we present future research directions for developing novel QoE measurement and prediction technique

Preserving Local Wisdom in the Leadership of Islamic University Libraries in Yogyakarta

This research tries to understand how the preservation of local wisdom in the leadership of Islamic university libraries in Yogyakarta, viewed from policies and programs that have been done, refers to the local value that is believed by people in Indonesia. The research is aimed at illustrating the importance of local wisdom values as a leadership identity in the libraries. The research employs qualitative descriptive apporach. The results of the research show that the libraries of Indonesian Islamic University and Sunan Kalijaga State Islamic University in Yogyakarta have already embedded the values of communal work and consensus as referent in every policy and solution for their problems. Background Nowadays, internalization of local wisdom into library leadership concept is absolutely necessary and needs to be discussed in both academic and practical ways. The local wisdom has become important to be preserved in library leadership because it reflects original values of society. According to Sulistyo-Basuki (2002, p. 29), a library in its history is created and maintained by the community as a means of preserving knowledge that will become a main capital to build a new civilization. A library in its function of preserving local wisdom is not only limited to the preservation of heritage in the form of text, but also the exprerience values contained should become a philosophy of life inherent in the library leadership concept. According to John Budd and Anne Goulding cited in Lisa Hussey (2012, p. 48), the library has a role in the field of cultural production, such as facilitator, agent of preservation, builder of repository culture, and actor implementing cultural value in the management of libraries. In order to create a cultural values-based leadership, the libraries should be managed through local wisdom approach. According to Ridwan in Wikantiyoso (2009, p. 6), local wisdom is a good behavior of people in relation to their environment. It is derived from religious values, customs, advices of ancestors, and local culture, which have scientifically awakened communities to adapt their surroundings. It is distinctively characterized as dynamic, continuous, and binds to the community. The implementation of local wisdom in the library leadership is meant as a practical form of noble values among society. Setyowati (2013, p. 104) states that leadership is a process of influencing a group to achieve 1 LIS Graduate Program, Sunan Kalijaga State Islamic University, Yogyakarta, Indonesia - [email protected] 2 LIS Graduate Program, Sunan Kalijaga State Islamic University, Yogyakarta, Indonesia - [email protected] Keywords: local wisdom, leadership, Islamic university library, UIN Sunan Kalijaga, Indonesian Islamic University (UII

Correlated multi-streaming in distributed interactive multimedia systems

Distributed Interactive Multimedia Environments (DIMEs) enable geographically distributed people to interact with each other in a joint media-rich virtual environment for a wide range of activities, such as art performance, medical consultation, sport training, etc. The real-time collaboration is made possible by exchanging a set of multi-modal sensory streams over the network in real time. The characterization and evaluation of such multi-stream interactive environments is challenging because the traditional Quality of Service metrics (e.g., delay, jitter) are limited to a per stream basis. In this work, we present a novel ???Bundle of Streams??? concept to de???ne correlated multi-streams in DIMEs and present new cyber-physical, spatio-temporal QoS metrics to measure QoS over bundle of streams. We realize Bundle of Streams concept by presenting a novel paradigm of Bundle Streaming as a Service (SAS). We propose and develop SAS Kernel, a generic, distributed, modular and highly ???exible streaming kernel realizing SAS concept. We validate the Bundle of Streams model by comparing the QoS performance of bundle of streams over different transport protocols in a 3D tele-immersive testbed. Also, further experiments demonstrate that the SAS Kernel incurs low overhead in delay, CPU, and bandwidth demands