Investigation of path loss prediction in different multi-floor stairwells at 900MHz and 1800MHz

Wireless communication along the stairwell in a high rise building is important to ensure immediate response to take place via consistent relaying of necessary information or data in emergency situations. Thus, a good understanding of signal wave attenuation along the stairwell is necessary to allow a better wireless network planning. This paper presents empirical path loss prediction model for multi-floor stairwell environment. The proposed model is based on measurement at 4 different stairwells, at 900MHz and 1800 MHz which are near public safety communication bands. The model incorporates the effect of different floor heights and unique path loss-to-distance relation on selected stair flights observed during measurement campaign. The proposed model demonstrates higher accuracy than 3 standard path loss models at 2 other stairwell

A multi band mini printed omni directional antenna with v-shaped for RFID applications

This paper presents a mini multi-band printed omni-directional antenna with v-shaped structure for radio frequency identification (RFID) applications. The proposed multi-band antenna is developed from the initial v-shaped design which is only capable of working as a single-band antenna. By deploying a concept of dipole antenna to an initial design, the proposed antenna is accomplished to operate with two different modes of RFID system which are passive and active modes at frequencies of 915MHz and 2.45 GHz respectively. The passive RFID tag is invented when a chip of Ultra High Frequency (UHF) is integrated with a proposed multi-band antenna. This passive tag, which is able to radiate with the measured signal strength, shows that the reading ranges are boosted almost two times compared to the conventional inlay antenna. The maximum reading range of passive RFID tag with inlay antenna is 5 m, though a reading range up to 10m is achievable through the deployment of the proposed antenna at a measurement field. Implicitly, the measurements carried out on the antenna are in good agreement with the simulated values. Moreover, the size of the mobile passive RFID tag has been substantially as 100mm × 70 mm, even though the antenna is fabricated with an inexpensive FR-4 substrate material. With the reasonable gain, coupled with cheaper material and smaller size, the proposed antenna has attractive potentials for use in RFID applications with multiple frequency antenna for active and passive tags

Active RFID Technology for Asset Tracking and Management System

 Asset is one of valuable item in the industry or institution, missing or lose of asset may have problem in asset management system. The advantages of Radio Frequency Identification (RFID) technology have made this technology useful for asset management and tracking system. The use of active RFID technology for asset tracking is by attaching the tag at the asset or item with assigned a unique ID for identification. A few of active RFID readers install at strategic points or location to track asset movement and collect information when anyone of item pass by in reader coverage area, reader collect information with in reading range and send to backend system. Integration every single system by using wires or wireless methods to keep centralize data processing system. Alert message will be send to representative department to give warning. This asset tracking and management system that use active type of RFID technology is working at ISM band frequency of 433 MHz. The backend systems consist of application software, middleware and database. All the information have been sent from every single system recorded in one central database

UHF RFID Tag Antenna for Vehicle License Plate Number (e-Plate)

 In this research presents a new design of UHF RFID tag antenna for vehicle license plate number (e-plate). The proposed e-plate does not require another gadget or equipment since every vehicle is attached with a vehicle registration plate number and this e-plate embedded together. A low cost FR4 material has been used for its fabrication and there is performance improvement compared to the current tag antenna. The proposed antenna design works at 902-928 MHz frequency band for UHF RFID application with 3.8 dBi antenna gain. The antenna is rectangular in shape and has a dimension of 300 mm x 100 mm, which is usually the typical size of the conventional vehicle registration plate number. Acceptable responses were obtained in simulation at centre frequency of 915 MHz with reflection coefficient of -57.7 dB.  The performance of proposed e-plate antenna was further tested by attaching a RFID tag chip and embedded it to the actual vehicle plate number. Initial testing on the field by attached e-plate on vehicle was achieved maximum reading range of up to 12 meters

Coverage Range and Cost Comparison of Remote Antenna Unit Designs for Inbuilding Radio over Fiber Technology

Future communication needs to be ubiquitous, broadband, convergent, and seamless. Radio over fiber (RoF) technology is one of the most important enabler in access network for the technologies. Adoption of RoF faces bottleneck in optoelectronics, that they are still expensive, high power consumption, and limited in bandwidth. To solve the problem, transceiver in remote antenna unit (RAU) is developed, i.e. electroabsorption transceiver (EAT) and asymmetric FabryPerot modulator (AFPM). This paper compares their coverage range and cost in providing WCDMA and WLAN services. Needed gain of RF amplifier for supporting picocell is also discussed

Comparative studies of the rain attenuation predictions for tropical regions

The radio waves propagating through the earth atmosphere will be attenuated due to the presence of atmosphere particles, such as water vapor, water drops and the ice particles. Meanwhile, the atmospheric gases and rain will both absorb and scatter the radio waves, and consequently degrade the performance of the link. The results of various studies conducted in temperate and tropical regions have been published in research papers. This paper presents the summary of comparative studies on different rain attenuation prediction methods for terrestrial microwave links tropical regions. Basically the models described in this paper include those of the ITU-R, revised Moupfouma, revised Silva Mello and Lin model. The objective of this study is to reveal the most suitable rain attenuation prediction model for the Malaysian tropical region. This paper will provide useful information for microwave engineers and researchers in making decision over the choice of most suitable rain attenuation prediction for terrestrial links operating in a tropical region. Even though the ITU-R model underestimates the rain attenuation at higher frequencies, the test results have clearly indicated that it is most suitable for predicting terrestrial rain attenuation in tropical Malaysia, compared to others

A radiometeorological study based on data from Malaysia and Amazon Region

Based on rain gauge and radar measurements carried out in Malaysia and Amazon region (Brazil), this paper deals with the description of meteorological factors affecting the radio wave propagation in low latitude areas. As it will be shown along the paper, in spite of the large geographical separation between these two countries similar results have been observed. In this context, the following topics are discussed: a) Climatic classification; b) Rainfall rate features, including the prediction of annual and worst month cumulative distributions; c) Horizontal and vertical spatial distribution of precipitation; d) Path length factor and effective rain height associated, respectively, to terrestrial and Earth-space radio links. The concepts and experimental data presented here are of fundamental relevance for rain attenuation studies at frequencies above 10 GHz in the equatorial region of the world

Comparison of microwave path lengths between temperate and tropical region based on effects of rain

Rain is a major source of attenuation for microwave propagation above 7 GHz. The problem of rain attenuation prediction has been studied along the years. In spite of the e®ort developed in di®erent parts of the world, there are yet some points to be clari¯ed. This problem is quite di±cult to be solved, mainly due to the complexity of rain structure. This clearly suggests that reduction factor is the major yardstick for comparing rain attenuation prediction models. However, important parameter need to consider in the path reduction factor is the maximum e®ective path length for a particular link at speci¯c operating frequency. This paper presents the summary of allowable path length for designing terrestrial microwave link at particular operating frequency at temperate and tropical region. The objective of this paper, to establish the maximum path length or hop length for terrestrial link on line of sight point to point communication at 99.99% of availability. Various frequency band such as 7 GHz, 15 GHz, 23 GHz, 26 GHz and 38 GHz been investigated using the ITU-R path reduction model. From the studies conducted, there are signi¯cant di®erences in path length between temperate region and tropical region. The di®erences are 22 km, 10 km, 5 km, 4km and 3km in the path length for operating frequency 7 GHz, 15 GHz, 23 GHz, 26 GHz & 38 GHz. This paper will provide useful information for microwave engineers and researchers in making valuable decision on path length for any terrestrial links point to point communication operating in a temperate and tropical region in future

Mitigation technique for rain fade using frequency diversity method

The radio waves propagating through the earth atmosphere is particles, such as water vapor, water drops and the ice particles. The atmospheric gases and rain both absorb and scatter the radio waves, and consequently degrade the performance of the microwave link. Millimeter wave (mmWave) is today's breakthrough frontier for emerging wireless mobile cellular networks, wireless local area networks, personal area networks, and vehicular communications. In the near future, mmWave products, systems, theories, and devices will come together to deliver mobile data rates thousands of times faster than today's existing cellular and WiFi networks for an example from the era of 3G towards 5G mobile communication near future.. However for Tropical countries the data link realibility is effected during rain. Rain is a major source of attenuation for microwave propagation above 7 GHz [1]. In tropical and equatorial regions, the rain intensity is higher and designing terrestrial and earth-to-satellite microwave links are very critical and challenging for high frequencies. This paper presents the summary of rain effects studies for lower operating frequency such as C band compare to higher operating frequency such as Ka band in tropical environment. The main objective is to justify the literature findings on the effect of rain at lower and higher operating frequency in microwave link and solution to overcome it by implementing Switching Circuit as Fade Mitigation Technique (FMT). An experimental test bed has been set up for 5.8 GHz and 26 GHz terrestrial point to point data communication link. The received signal strength (RSS) data and rain fall intensity data were recorded for 24 hours daily over period of 12 months (Jan 2013 – Dec 2013) at 1 minute interval. The collected rain rate data has been analyzed with some prediction models. The main outcome of the research shows that there is negligible effect of rain for 5.8 GHz link whereas it very strong on the 26 GHz link. It was observed 15 dB to 35 dB attenuation during measurement period. The FMT used in this research for dual frequency by shifting the operating frequency to lower band (5.8 GHz) while heavy rain and shifting back to normal position at higher operating frequency (26 GHz) using the threshold level as reference seems to be one of the solution in future. This findings will be useful resources of information for researchers or telecommunication engineers