- On the Behavior of Communication Links in a Multi-Hop Mobile Environment

2016 ◽  
pp. 704-729 ◽  
Keyword(s):  
Mobile Environment ◽  
Communication Links

Handoff Schemes in Mobile Environments

2020 ◽  
Vol 11 (1) ◽  
pp. 55-72
Author(s):  
Libin Thomas ◽  
J Sandeep ◽  
Bhargavi Goswami ◽  
Joy Paulose
Keyword(s):  
Ad Hoc Networks ◽  
Vehicular Ad Hoc Networks ◽  
Ad Hoc ◽  
Mobile Environments ◽  
Mobile Nodes ◽  
Mobile Environment ◽  
Coverage Area ◽  
Communication Links ◽  
Hoc Networks ◽  
Handoff Schemes

Vehicular ad-hoc networks are one of the most popular applications of Ad-hoc networks, where networks are formed without any sort of physical connecting medium and can be formed whenever required. It is an area in networks that has enjoyed a considerable amount of attention for quite some time. Due to the highly mobile environment where these networks find their usability, it can be understood that there are a lot of problems with respect to maintaining the communication links between the moving vehicular nodes and the static infrastructures which act as the access points (AP) for these moving vehicular mobile nodes (MN). The coverage area of each AP is limited and as such, the connections need to be re-established time and again between the MNs and the closest accessible AP. Handoff is the process involved here, which deals with selecting the optimal APs as well as the best network available for data transmission. In this article, the authors compare various handoff methods and categorize them based on the different approaches they follow.

ESTIMATION OF RAIN FADE DURATIONS ON COMMUNICATION LINKS AT Ka BAND IN EQUATORIAL AND TROPICAL REGIONS

2020 ◽  
Vol 79 (2) ◽  
pp. 129-141
Author(s):  
M. E. Sanyaolu ◽  
Oluropo F. Dairo ◽  
A. A. Willoughby ◽  
L. B. Kolawole
Keyword(s):  
Ka Band ◽  
Tropical Regions ◽  
Communication Links

Optical data signals in fiber optic communication links with fading

2019 ◽  
pp. 94-104
Author(s):  
I. Juwiler ◽  
I. Bronfman ◽  
N. Blaunstein
Keyword(s):  
Spectral Efficiency ◽  
Fiber Optic ◽  
Fiber Optic Cable ◽  
Optical Signals ◽  
Dispersion Properties ◽  
Optical Cable ◽  
Time Dispersion ◽  
Communication Links ◽  
Fiber Optic Communication ◽  
Optic Communication

Introduction: This article is based on the recent research work in the field of two subjects: signal data parameters in fiber optic communication links, and dispersive properties of optical signals caused by non-homogeneous material phenomena and multimode propagation of optical signals in such kinds of wired links.Purpose: Studying multimode dispersion by analyzing the propagation of guiding optical waves along a fiber optic cable with various refractive index profiles of the inner optical cable (core) relative to the outer cladding, as well as dispersion properties of a fiber optic cable due to inhomogeneous nature of the cladding along the cable, for two types of signal code sequences transmitted via the cable: return-to-zero and non-return-to-zero ones.Methods: Dispersion properties of multimode propagation inside a fiber optic cable are analyzed with an advanced 3D model of optical wave propagation in a given guiding structure. The effects of multimodal dispersion and material dispersion causing the optical signal delay spread along the cable were investigated analytically and numerically.Results: Time dispersion properties were obtained and graphically illustrated for two kinds of fiber optic structures with different refractive index profiles. The dispersion was caused by multimode (e.g. multi-ray) propagation and by the inhomogeneous nature of the material along the cable. Their effect on the capacity and spectral efficiency of a data signal stream passing through such a guiding optical structure is illustrated for arbitrary refractive indices of the inner (core) and outer (cladding) elements of the optical cable. A new methodology is introduced for finding and evaluating the effects of time dispersion of optical signals propagating in fiber optic structures of various kinds. An algorithm is proposed for estimating the spectral efficiency loss measured in bits per second per Hertz per each kilometer along the cable, for arbitrary presentation of the code signals in the data stream, non-return-to zero or return-to-zero ones. All practical tests are illustrated by MATLAB utility.

Synchronization and replication model in mobile environment

2009 ◽  
Vol 28 (10) ◽  
pp. 2544-2547
Author(s):  
Li-sheng CHEN ◽  
Hai-bin GUO ◽  
Fei-yue YE
Keyword(s):  
Mobile Environment ◽  
Replication Model
Sign in / Sign up

Export Citation Format

Share Document