Adaptive and cognitive radios (CR) have been becoming popular for optimizing mobile radio system transmission and reception. One of the most important elements of the adaptive radio and CR concepts is the ability to measure, sense, learn about, and be aware of parameters related to the radio channel characteristics, availability of spectrum and power, interference and noise temperature, operati...

Third generation mobile radio systems will employ TD-CDMA in their TDD mode. In a TD-CDMA mobile radio system, jointdetection is equivalent to solving a least squares problem with a block-Toeplitz system matrix. By extending this matrix to a block-circulant matrix, it is possible to blockdiagonalize the matrix with Fast Fourier Transforms. For the typical system scenario of a TD-CDMA system, th...

The aim of this paper is to show the special characteristics of the indoor environment related to radio propagation and furthermore to radio network planning. The aspects of the radio network planning are highlighted especially for Wideband Code Division Multiple Access (WCDMA) radio access technology that is used widely in the third generation mobile networks. Moreover, the detailed planning p...

Machine-to-Machine (M2M) communications is one of the main new areas of future mobile networks. There are many applications of M2M communications such as intelligent transport systems, smart metering and monitoring, and health care. These applications use a large number of mobile devices which can generate a huge amount of traffic along with different QoS requirements. Due to the mobility, most...

NTT DOCOMO is currently studying a fifth-generation mobile communications system (5G) intensely. This system is expected to use high frequency bands, so clarification of the propagation characteristics in these high frequency bands is the most important issue in radio propagation research for 5G. This article gives an overview of the issues and current state of study in radio propagation, and d...

The traffic performance of third generation mobile systems is greatly influenced by the multiple access protocols used in the radio access subsystem. The paper introduces an access protocol, SIR (Service Integration Radio Access), which has the potential for accommodating the requirements of speech and bursty data traffic in an efficient way. SIR is evolved from a protocol (PRMA++) studied in t...

This paper describes the architecture and implementation of a mobile IP system. It allows mobile hosts to roam between cells implemented with 2-Mbps radio base stations, while maintaining Internet connectivity. The system is being developed as part of a course on wireless networks at Harvard and has been operational since March 1994. The architecture scales well, both geographically and in the ...

The paper presents a comparison of different radio over fibre system concepts with regard to applications in broadband services transmission. Several concepts of radio over fibre systems have been studied around the world, and each of them seems to be very attractive because of low loss and extremely wide bandwidth necessary for mobile broadband services. Commercial deployment of the millimeter...

Mobile phones work by transmitting and receiving radio frequency microwave radiation. The radio frequency (RF) emitted by mobile phones is stronger than FM radio signal which are known to cause cancer. Though research and evidence available on the risk of cancer by mobile phones does not provide a clear and direct support that mobile phones cause cancers. Evidence does not also support an assoc...