scholarly journals A Novel Handoff Necessity Estimation Approach Based on Travelling Distance

Author(s):  
Jyoti Madaan ◽  
Indu Kashyap

<p><em>Mobility management is one of the most important challenges in Next Generation Wireless Networks (NGWNs) as it enables users to move across geographic boundaries of wireless networks. Nowadays, mobile communications have heterogeneous wireless networks offering variable coverage and Quality of Service (QoS). The availability of alternatives generates a problem of occurrence of unnecessary handoff that results in wastage of network resources. To avoid this, an efficient algorithm needs to be developed to minimize the unnecessary handoffs. Conventionally, whenever  Wireless Local Area Network (WLAN) connectivity is available, the mobile node switch from cellular network to wireless local area network  to gain maximum use of high bandwidth and low cost of wireless local area network as much as possible. But to maintain call quality and minimum number of call failure, a considerable proportion of these handovers should be determined. Our algorithm makes the handoff to wireless local area network only when the Predicted Received Signal Strength (PRSS) falls below a threshold value and travelling distance inside the wireless local area network is larger than a threshold distance.Through MATLAB simulation, we show that our algorithm is able to improve handover performance.<strong> </strong></em></p>

2013 ◽  
Vol 468 ◽  
pp. 141-144
Author(s):  
Su Hua Chen ◽  
Yong Guang Liu ◽  
Xu Fang

Smart home system mainly consists of home networking, wireless local area network and external network, and with the advantages of low cost and high reliability, Zigbee wireless technology is the right choice for smart home system and the main part of home networking. The design of smart home system based on Zigbee is proposed, the Zigbeethe design process of the systemintelligent socket and data communication rule are elaborated. The system has been applied in smart community of Shaoxing Electric Power Bureau, which has good performances, high availability and reliability, better market prospects.


T-Comm ◽  
2021 ◽  
Vol 15 (7) ◽  
pp. 28-33
Author(s):  
Albina Y. Sharifullina ◽  
◽  
Roman R. Galyamov ◽  
Rimma S. Zaripova ◽  
◽  
...  

This article discusses the stages of development, characteristics of a wireless local area network Wi-Fi, options for its topology and equipment used. Currently, there are such different types of wireless networks as Wireless Wide Area Network, Wireless Metropolitan Area Networks (Wireless Neighborhood Area Network), Wireless Local Area Network, Wireless Personal Area Network. Each of the listed wireless networks has its own specific range and application. Wireless LAN Wi-Fi refers to the Wireless Local Area Network. The first wireless LAN standard, Wi-Fi, was approved in 1997. From the moment of their appearance to the present day, the following standards of this network have appeared: 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, 802.11ad, 802.11ax. For each standard, the speeds and frequency ranges at which the data transmission was carried out are indicated, and the technologies on which they are built are described. Wireless LAN Wi-Fi has three topologies: 1) Ad-Hoc (point-to-point) or Independent Basic Service Set; 2) Basic Service Set (“client / server”) and 3) Extended Service Set (“extended service areas”). To build a Wi-Fi network, network adapters, access points, routers, ADSL modems, Wi-Fi phones, Wi-Fi antennas, Wi-Fi repeaters are used. Wi-Fi adapters are used by devices that do not have a built-in Wi-Fi module. Wi-Fi access points are designed for organizing wireless access within a local network. Wi-Fi routers are designed to route traffic on a computer network. ADSL modems are used to access the Internet over a telephone line. Wi-Fi repeaters are used to expand the coverage of a wireless network using already installed equipment. Wi-Fi phones are wireless IP phones. Wi-Fi antennas are used to extend the range of a wireless network.


Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1007
Author(s):  
Zhuohang Zhang ◽  
Zhongming Pan

A novel reconfigurable filter antenna with three ports for three dependent switchable states for impulse radio-ultrawideband (IR-UWB)/wireless local area network (WLAN)/worldwide interoperability for microwave access (WiMAX) applications is presented in this paper. Three positive-intrinsic-negative diodes, controlled by direct current, are employed to realize frequency reconfiguration of one ultra-wideband state and two narrowband states (2.4 GHz and 3.5 GHz). The time domain characteristic of the proposed antenna in the ultra-wideband state is studied, because of the features of the IR-UWB system. The time domain analysis shows that the reconfigurable filtering antenna in the wideband state performs similarly to the original UWB antenna. The compact size, low cost, and expanded reconfigurable filtering features make it suitable for IR-UWB systems that are integrated with WLAN/WiMAX communications.


Author(s):  
Jagannath Malik ◽  
Parth C. Kalaria ◽  
Machavaram V. Kartikeyan

In the present study, an ultra-wideband (UWB) antenna has been proposed using coplanar waveguide (CPW) feed with dual-band-notch characteristics. Slot-loaded radiator and U-shaped CPW resonator are used for band rejection at 3.5 and 5–6 GHz respectively to reduce interference with existing World interoperability for microwave access and wireless local area network systems. With an extended operating band (measured at 10 dB return loss) the antenna operates successfully over the entire UWB range (3.1–10.6 GHz) with a form factor of 30 × 20 × 1.524 mm3 on a commercially low-cost FR-4 substrate. Experimental measurement results are presented in support of the simulated results for the proposed antenna for practical application. The antenna has been successfully fabricated and measured, showing broadband matched impedance and good omnidirectional radiation pattern throughout the operating bandwidth. Measured time-domain analysis for both the orientations, i.e. face-to-face and side-by-side, yields excellent performance in the open environment scenario. With fairly good and consistent monopole such as omnidirectional radiation patterns in H-plane and linear transmission responses, the proposed antenna is well suited to be integrated within portable devices.


2019 ◽  
Vol 29 (03) ◽  
pp. 2050050
Author(s):  
Biplab Bag ◽  
Priyabrata Biswas ◽  
Sushanta Biswas ◽  
Partha Pratim Sarkar ◽  
Dibyendu Ghoshal

In this paper, two novel low-profile monopole antennas are presented for simultaneous operation in GPS (Global Positioning System), WLAN (Wireless Local Area Network) and WiMAX (Worldwide Interoperability for Microwave Access) applications. The antennas constitute of a T-shaped microstrip feed line and directly coupled strips to generate multiple bands. The proposed antennas are printed on one side of a low-cost FR4 epoxy substrate and partial ground plane (metal plane is etched partially) are fabricated on the other side of the substrate. The overall dimension of antenna is [Formula: see text][Formula: see text]mm3. Measured results show that the antenna1 (quad band) covers the four distinct operating bands of 320[Formula: see text]MHz (2.17–2.49[Formula: see text]GHz), 190[Formula: see text]MHz (3.31–3.50[Formula: see text]GHz), 270[Formula: see text]MHz (5.18–5.45[Formula: see text]GHz) and 700[Formula: see text]MHz (5.5–6.20[Formula: see text]GHz). Antenna2 (penta band) covers the frequency bands of 1.29–1.98[Formula: see text]GHz (center frequency 1.61[Formula: see text]GHz), 2.78–2.91[Formula: see text]GHz (center frequency 2.83[Formula: see text]GHz), 3.59–3.94[Formula: see text]GHz (center frequency 3.75[Formula: see text]GHz), 5.15–5.33[Formula: see text]GHz (center frequency 5.24[Formula: see text]GHz) and 5.39–6.06[Formula: see text]GHz (center frequency 5.56[Formula: see text]GHz). The detail antenna design and parametric analyses are discussed in steps. The characteristic of radiation pattern and gain are measured. The measured and simulated results are in good agreement. The antennas are designed using a simulation software HFSS v.15.


2016 ◽  
Vol 9 (5) ◽  
pp. 1123-1129 ◽  
Author(s):  
Wang Ren ◽  
Shu-Wei Hu ◽  
Chen Jiang

In this paper, an asymmetric coplanar strip (ACS)-fed quad-band monopole antenna for the global positioning system (GPS), wireless local area network (WLAN), and worldwide interoperability for microwave access (WiMAX) applications is proposed. It is composed of an F-shaped monopole and a partial ground plane, which are both printed on one side of a low-cost FR4 substrate with a compact volume of 40 × 20 × 1.6 mm3. By cutting an open-ended Γ-shaped slot into the F-shaped monopole, four distinct resonant modes are successfully generated. The design process, especially the geometrical configuration of the critical Γ-shaped slot is studied in detail. The proposed antenna has been fabricated and experimental results show that the −10 dB impedance bandwidth can fully cover the 1.575-GHz GPS (1.57–1.59 GHz), 2.4/5.2/5.8-GHz WLAN (2.4–2.485, 5.15–5.35, and 5.725–5.825 GHz), and 2.5/3.5/5.5-GHz WiMAX (2.50–2.69, 3.30–3.70, and 5.25–5.85 GHz) applications with nearly omni-directional radiation patterns and satisfactory gains.


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