10,295 research outputs found
Wireless Networking to Support Data and Voice Communication Using Spread Spectrum Technology in The Physical Layer
Wireless networking is rapidly growing and becomes an inexpensive technology
which allows multiple users to simultaneously access the network and the
internet while roaming about the campus. In the present work, the software
development of a wireless LAN(WLAN) is highlighted. This WLAN utilizes direct
sequence spread spectrum (DSSS) technology at 902MHz RF carrier frequency in
its physical layer. Cost effective installation and antijaming property of
spread spectrum technology are the major advantages of this work.Comment: international conference on information technology, March 2007. 7
pages,4 figures, 2 table
Wireless Lan to Support Multimedia Communication Using Spread Spectrum Technology
Wireless LAN is currently enjoying rapid deployment in University
departments, business offices, hospitals and homes. It becomes an inexpensive
technology and allows multiple numbers of the households to simultaneously
access the internet while roaming about the house. In the present work, the
design and development of a wireless LAN is highlighted which utilizes direct
sequence spread spectrum (DSSS) technology at 900MHz RF carrier frequency in
its physical layer. This provides enormous security in the physical layer and
hence it is very difficult to hack or jam the network. The installation cost is
also less due to the use of 900 MHz RF carrier frequency..Comment: URSI 0ctober 22-29 2005, 4pages, 6 figure
Aeronautical Ad Hoc Networking for the Internet-Above-The-Clouds
The engineering vision of relying on the ``smart sky" for supporting air
traffic and the ``Internet above the clouds" for in-flight entertainment has
become imperative for the future aircraft industry. Aeronautical ad hoc
Networking (AANET) constitutes a compelling concept for providing broadband
communications above clouds by extending the coverage of Air-to-Ground (A2G)
networks to oceanic and remote airspace via autonomous and self-configured
wireless networking amongst commercial passenger airplanes. The AANET concept
may be viewed as a new member of the family of Mobile ad hoc Networks (MANETs)
in action above the clouds. However, AANETs have more dynamic topologies,
larger and more variable geographical network size, stricter security
requirements and more hostile transmission conditions. These specific
characteristics lead to more grave challenges in aircraft mobility modeling,
aeronautical channel modeling and interference mitigation as well as in network
scheduling and routing. This paper provides an overview of AANET solutions by
characterizing the associated scenarios, requirements and challenges.
Explicitly, the research addressing the key techniques of AANETs, such as their
mobility models, network scheduling and routing, security and interference are
reviewed. Furthermore, we also identify the remaining challenges associated
with developing AANETs and present their prospective solutions as well as open
issues. The design framework of AANETs and the key technical issues are
investigated along with some recent research results. Furthermore, a range of
performance metrics optimized in designing AANETs and a number of
representative multi-objective optimization algorithms are outlined
Performance Analysis and Special Issues of Broadband Strategies in the Computer Communication
Broadband communications consists of the technologies and equipment required
to deliver packet-based digital voice, video, and data services to end users.
Broadband affords end users high-speed, always-on access to the Internet while
affording service providers the ability to offer value-added services to
increase revenues. Due to the growth of the Internet, there has been tremendous
buildout of high-speed, inter-city communications links that connect population
centers and Internet service providers (ISPs) points of presence (PoPs) around
the world. This build out of the backbone infrastructure or core network has
occurred primarily via optical transport technology. Broadband access
technologies are being deployed to address the bandwidth bottleneck for the
"last mile," the connection of homes and small businesses to this
infrastructure. One important aspect of broadband access to the home is that it
allows people to telecommute effectively by providing a similar environment as
when they are physically present in their office: simultaneous telephone and
computer access, high-speed Internet and intranet access for e-mail, file
sharing, and access to corporate servers.Comment: 16 page
Low Power Wide Area Networks: An Overview
Low Power Wide Area (LPWA) networks are attracting a lot of attention
primarily because of their ability to offer affordable connectivity to the
low-power devices distributed over very large geographical areas. In realizing
the vision of the Internet of Things (IoT), LPWA technologies complement and
sometimes supersede the conventional cellular and short range wireless
technologies in performance for various emerging smart city and
machine-to-machine (M2M) applications. This review paper presents the design
goals and the techniques, which different LPWA technologies exploit to offer
wide-area coverage to low-power devices at the expense of low data rates. We
survey several emerging LPWA technologies and the standardization activities
carried out by different standards development organizations (e.g., IEEE, IETF,
3GPP, ETSI) as well as the industrial consortia built around individual LPWA
technologies (e.g., LORa Alliance,WEIGHTLESS-SIG, and DASH7 Alliance). We
further note that LPWA technologies adopt similar approaches, thus sharing
similar limitations and challenges. This paper expands on these research
challenges and identifies potential directions to address them. While the
proprietary LPWA technologies are already hitting the market with large
nationwide roll-outs, this paper encourages an active engagement of the
research community in solving problems that will shape the connectivity of tens
of billions of devices in the next decade.Comment: \c{opyright} 2017 IEEE. Personal use of this material is permitted.
Permission from IEEE must be obtained for all other uses, in any current or
future media, including reprinting/republishing this material for advertising
or promotional purposes, creating new collective works, for resale or
redistribution to servers or lists, or reuse of any copyrighted component of
this work in other work
HELPER: Heterogeneous Efficient Low Power Radio for Enabling Ad Hoc Emergency Public Safety Networks
Natural and man-made disasters have been causing destruction and distress to
humanity all over the world. In these scenarios, communication infrastructures
are the most affected entities making emergency response operations extremely
challenging. This invokes a need to equip the affected people and the emergency
responders with the ability to rapidly set up and use independent means of
communication. Therefore, in this work, we present a complete end-to-end
solution that can connect survivors of a disaster with each other and the
authorities using a completely self-sufficient ad hoc network that can be setup
rapidly. Accordingly, we develop a Heterogeneous Efficient Low Power Radio
(HELPER) that acts as an access point for end-users to connect using custom
website application. These HELPERs then coordinate with each other to form a
LoRa based ad hoc network. To this end, we propose a novel cross-layer
optimized distributed energy-efficient routing (SEEK) algorithm that aims to
maximize the network lifetime. The HELPER is prototyped using WiFi enabled
Raspberry Pi and LoRa module that is configured to run using Li-ion batteries.
We implement the required cross-layer protocol stack along with the SEEK
routing algorithm. We have conducted demonstrations to establish the
feasibility of exchanging of text messages over the HELPER network, live map
updates, ability to send distress messages to authorities. Emergency responders
can leverage this technology to remotely monitor the connectivity of the
affected area and alert users of imminent dangers. SEEK algorithm was shown to
outperform a greedy geographical routing algorithm implemented on HELPER
testbed by up to 53 % in terms of network lifetime and up to 28 % in terms of
throughput. Overall, we hope this technology will become instrumental in
improving the efficiency and effectiveness of public safety activities
A Survey on High-Speed Railway Communications: A Radio Resource Management Perspective
High-speed railway (HSR) communications will become a key feature supported
by intelligent transportation communication systems. The increasing demand for
HSR communications leads to significant attention on the study of radio
resource management (RRM), which enables efficient resource utilization and
improved system performance. RRM design is a challenging problem due to
heterogenous quality of service (QoS) requirements and dynamic characteristics
of HSR wireless communications. The objective of this paper is to provide an
overview on the key issues that arise in the RRM design for HSR wireless
communications. A detailed description of HSR communication systems is first
presented, followed by an introduction on HSR channel models and
characteristics, which are vital to the cross-layer RRM design. Then we provide
a literature survey on state-of-the-art RRM schemes for HSR wireless
communications, with an in-depth discussion on various RRM aspects including
admission control, mobility management, power control and resource allocation.
Finally, this paper outlines the current challenges and open issues in the area
of RRM design for HSR wireless communications.Comment: 40 pages, 10 figures. Submitted to Computer Communication
Wi-Fi & WiMAX: A Comparative Study
Usually broadband wireless access networks are considered to be enterprise
level networks providing us with more capacity as well as coverage. We have
seen that in remote inaccessible areas wired networks are not at all cost
effective. Wireless networking has offered us an alternative solution for such
problem of information access. They have definitely changed the way people
communicate and share information among themselves by overcoming problems
nowadays associated with distance and location. This paper provides a
comparison and technical analysis of alternatives for implementing last-mile
wireless broadband services. It provides detailed technical differences between
802.11 (Wi-FI) wireless networks with 802.16 (WiMAX), a new technology that
solves many of the difficulties in last-mile implementations.Comment: 5 pages, 4 figures, 1 tabl
Towards combinatorial modeling of wireless technology generations
The paper addresses the following problems: (1) a brief survey on wireless
mobile communication technologies including evolution, history evolution (e.g.,
chain of system generations 0G, 1G, 2G, 3G, 4G, 5G, 6G, 7G); (2) using a
hierarchical structural modular approach to the generations of the wireless
communication systems (i.e., hierarchical combinatorial modeling of the
communication technologies), (3) illustrative usage of two-stage combinatorial
approach to improvement/forecasting of the communication technology (a version
of 5G) (on the basis of multiple choice problem). Numerical examples illustrate
the suggested combinatorial approach.Comment: 20 pages, 13 figures, 9 table
A Novel Solution to the Short Range Bluetooth Communication
Bluetooth is developed for short range communication. Bluetooth Devices are
normally having low power and low cost. This is a wireless communication
technology designed to connect phones, laptops and PDAs. The greater
availability of portable devices with Bluetooth connectivity imposes wireless
connection between enabled devices. On an average the range of Bluetooth
devices is about 10 meters. The basic limitation of the Bluetooth communication
is this range limitation. In this paper I have studied the limitations of
Bluetooth communication and consider range constraint as the major limitation.
I propose a new expanded Blue tooth network to overcome the range constraint of
Bluetooth device. This creates a network of Bluetooth enabled devices that will
include laptops, set top devices and also mobile phones. The main purpose of
this proposal is to establish a network will enable the users to communicate
outside the range without any range constraint.Comment: 10 pages; IJANS-2011 October Issu
- …