In ad hoc mobile networks nodes typically communicate over wireless channels and are capable of movement. These are networks that support multihop communication and can be formed on a temporary basis. This paper evaluates a solution that allows mobile nodes to access the wired Internet and roam from base station to base station. The solution is based on the extension of Mobile IP capabilities t...

Two key problems need to be solved in order to realize soft handoff in wireless IP (Internet Protocol) networks: 1) Data distribution: multiple streams of the same IP traffic have to be distributed via multiple wireless base stations to the same mobile station, 2) Data content synchronization: pieces of data arriving at the mobile station at the same time from different base stations should be ...

In CDMA cellular networks, the soft handoff technique allows a mobile host to communicate with multiple base stations simultaneously, improving the transmission quality of the wireless channel and avoiding disconnection upon to base station switching. In this paper, we evaluate the influence of soft handoff on TCP (Transport Control Protocol) throughput in CDMA cellular networks through simulat...

This paper assesses radio frequency exposure of a mobile handset user in the context of a new class of cellular base station: the femtocell. Traditional cellular network construction relies on using a single base station to cover a large area and serve dozens to hundreds of users. The femtocell (named after the minuscule size of the coverage area) provides a low-power in-home cellular connectio...

In cellular wireless CDMA systems, it is required that the base station receives constant power signals from mobile users, in order to guarantee link quality. This is achieved by properly adjusting the uplink transmitted power of each mobile. Usually, the base station is responsible for informing each individual mobile of the power adjustment. However, when the radio channel varies drastically ...

Deploying relays and/or mobile base stations is a major means of extending the coverage of a wireless network. This paper presents models, analytical results, and algorithms to answer two related questions: The first is where to deploy relays in order to extend the reach from a base station to the maximum; the second is where to deploy a mobile base station and how many relays are needed to rea...

Having a holistic view on mobile user behavior will be increasingly difficult in the future where a fragmented user base is using multiple wireless access networks. To improve understanding on user behavior and mobile service usage, traditional survey based data collection can be complemented with a range of automated measurement methods. In this paper, the alternative data collection methods a...

The structure of OmniKity-I (OK-I), the miniature omni-directional mobile robot, and its kinematics and dynamics models are presented. OK-I has three DOFs in the plane. A conventional two wheeled mobile robot (2-WMR) serves as the base of OK-I for translational motion. The robot body is on top of the base. The third motor controls angular motion of the body as the base turns according to the tr...

Three mobile phone systems are used in Poland: analog, operated at the 450 MHz frequency range, and two digital systems operated at 900 MHz and 1800 MHz. The GSM--Global System for Mobile Communication meets all relevant requirements, and it is most widely used throughout the world. According to the mobile phone concept, the whole communication area is divided into sub-areas (cells) where base ...