Mobile telephony

About: Mobile telephony is a research topic. Over the lifetime, 38008 publications have been published within this topic receiving 553646 citations.

Multicarrier techniques for 4G mobile communications

Abstract: From the Publisher: As research for future fourth generation (4G) mobile communication systems is underway worldwide in major companies and academic institutions, forward-thinking professionals are striving to gain a thorough understanding of the cutting-edge technologies and design techniques that will make these systems work. This book helps readers do just that by: providing a comprehensive introduction to multicarrier techniques for 4G mobile communications with a special focus on the analytical aspects; explaining radio channel characteristics and phenomena and discussing the advantages and disadvantages of the OFDM scheme; featuring new multicarrier-related techniques, MC-CDMA, research on several 4G systems, and a look at several problems to be overcome with these systems; examining the concept and detail of the ODFM scheme and how to carry out theoretical analysis on the performance of transmission systems in radio channels; showing how ODFM has been successfully adopted as a modulation scheme in communications systems and broadcasting systems such as ADSL, wireless LANs, and DVB-T.

Mobile communications matching system

Abstract: A wireless communications network comprises a server in a central location storing matching profiles for a plurality of users of the network. The matching profile for each user is stored in the server through the user's mobile unit or a secure page on the Internet. Each matching profile is corresponded with a respective mobile unit using the same identification information (ID) of the respective mobile unit utilized for carrying out phone calls. The server has a customizable variable matching algorithm and probes the matching profiles corresponding to the respective mobile units in a cell or group of cells for a match every time a new mobile unit subscribes into the cell or group of cells. When there is a match of matching profiles, the two persons are put in contact or advised of each other through a phone call or other communications method.

Digital Footprinting: Uncovering Tourists with User-Generated Content

Abstract: Novel methods and tools are being developed to explore the significance of the new types of user-related spatiotemporal data. This approach helps uncover the presence and movements of tourists from cell phone network data and the georeferenced photos they generate. A city's visitors have many ways of leaving voluntary or involuntary electronic trails: prior to their visits, tourists generate server log entries when they consult digital maps or travel Web sites; during their visit, they leave traces on wireless networks whenever they use their mobile phones; and after their visit, they might add online reviews and photos. Broadly speaking then, there are two types of footprint: active and passive. Passive tracks are left through interaction with an infrastructure, such as a mobile phone network, that produces entries in locational logs; active prints come from the users themselves when they expose locational data in photos, messages, and sensor measurements. In this article, we consider two types of digital traces from Rome, Italy: georeferenced photos made publicly available on the photo-sharing Web site Flickr and aggregate records of wireless network events generated by mobile phone users making calls and sending text messages on the Telecom Italia Mobile (TIM) system.

EDGE: enhanced data rates for GSM and TDMA/136 evolution

Abstract: Two of the major second-generation standards, GSM and TDMA/136, have built the foundation to offer a common global radio access for data services. Through use of a common physical layer, EDGE, both standards will have the same evolutionary path toward providing third-generation services. EDGE is currently subject to standardization in TIA TR45.3 and ETSI SMG, a process which will be finalized at the end of 1999. Compared to the existing data services in GSM and TDMA/136, EDGE will provide significantly higher user bit rates and spectral efficiency. EDGE can be introduced in these systems in a smooth way, using existing frequency plans of already deployed networks. This article gives the rationale behind the development of the EDGE concept, presents the EDGE technology, and addresses performance by means of system simulations.