Computer Communications (Networks)

Computer Communications (Networks)

  • Shuaishuai Tan added an answer:
    Any help about adding new algorithm to OPNET modeler 14.5 ?

    I'm working in modifying existed protocol (OLSR) and I want to add this modification into OPNET modeler 14.5 to check if it works well or not. 

    References are better for helping and also any other tools 

    Shuaishuai Tan · Xidian University

    I have developed an MATLAB based program for simulating OLSR protocol (called MoSim) a few days ago, and it works well. MoSim supports mobility model, core functions of OLSR protocol, attack model, and provides functions of recording detailed simulation data, result analysis, showing topology with a graphic, etc. 

    However,the MoSim is not complete and needs a lot of improvement, such as adopting a more efficient software architecture, provides documents, etc.

    If you are interested in MoSim, contact me with without hesitate.

  • Anubhav Tewari added an answer:
    What are the possible ways of communication between femtocells belonging to different operators?

    Communication between femtocells. Is this even possible?!

    Anubhav Tewari · Shri Mata Vaishno Devi University

    The obvious idea is to make the channel protocol independent, i.e. both the operators will have their set of protocols, and will run on a protocol independent platform. Thus it is possible.

  • Abhishek Karwa added an answer:
    What is the difference between AWR, HFSS, ADS, CST?
    Under what circumstances and parameters is each best to be used? General Concept information about Microwave design softwares?
    Abhishek Karwa · JIET Group of Institutions

    I also need hfss related material at karwa_21@rediffmail.com

  • Jens Koopmann added an answer:
    In BPN, what kind of normalization technique can be used?

    I want to know whether zscore, biweight, minmax, or tanh can be used

    Jens Koopmann · www.biomarker-discovery.com

    Hi Rama,

    Do mind to expand on the background of your experiment. Study design etc. That would help to provide with the correct answer.

    Cheers

    Jens

  • Mohammadreza Amiri added an answer:
    Would you like to participate in a survey about M-learning?

    I am trying to carry out a survey on M-learning.

    It is 45 (choose from the list) questions which will take you about 10 minutes to complete, but it is vital for completing my research.
    Although the participation is voluntary, I would be grateful if you help me to do this survey. We will let you know the results by the time we analyzed the data.
    Please press following link to submit your responses:

    https://docs.google.com/forms/d/1YN5GRjuHhcODYCGQwjeWCXHERD5nj5JkGfvmiISjV7w/viewform

    Mohammadreza Amiri · University of Tehran

    Thanks Dear Ljubomir

  • Muhammad Zakarya added an answer:
    An ISI journal in the field of data center network architectures and topologies

    Hi all,

    As you know, there is a lot of ISI journals in the field of data center and interconnection network architectures and topologies. Which one do you suggest me to submit our research papers? Our paper is about "introducing a new topology (architecture) for data center and interconnection networks".

    I found several journals, but I want to have your suggestions, too.

    Thank you so much in advance.

    Muhammad Zakarya · Abdul Wali Khan University Mardan

    http://www.journalofcloudcomputing.com/about

  • Peter T Breuer added an answer:
    Can someone please let me know a custom card that can be connected to PCI?

    The card should have at least 9 pins each for AD and DA. Further, it should have atleast 10 pins for PWM/Encoder/Counter.

    Peter T Breuer · Birmingham City University

    Uh, Muhzir, I'm not sure, but I think he's talking about a custom card that can monitor an analog (A) signal or signals and digitize (D) it for the computer, NOT a device that connects to a modem... or he might be talking about digital audio (DA). Who knows!

    Of course, if the poster would actually explain himself, then we wouldn't have to guess. Communicating is a fundamentally human trait! I'm sure it can be managed, here too. Never use acronyms or jargon (shakes head); they're special shorthand for use between people who already know what domain they are talking about and cannot be used to establish context.

    "interface" to WHAT is the fundamental question!

    Doesn't the poster imagine that that might be necessary to know? Interface to plumbing? Interface to a TV. Interface to a fridge. Interface .... well, sure, I know plenty of PCI interface cards. There are ethernet cards, token ring adapters, digital audio pci cards, ....

    If none of those suit, he might google for something like PCI analog/digital conveter or sampler. The kind of thing one would use to monitor voltage levels from instruments on a field weather station. Or he might look in the Linux kernel for drivers for special pci cards. I'm sure he'll get good hints to what cards exist there....

    Say Y here if you want to build a driver for Sensable PHANToM device.

    If you say yes here you get support for the ALS APDS9802 ambient  light sensor.

    If you say yes here you get support for the Bosch Sensortec  BMP085 digital pressure sensor.

    The "Serial Peripheral Interface" is a low level synchronous protocol. Chips that support SPI can have data transfer rates up to several tens of Mbit/sec. Chips are addressed with a controller and a chipselect. Most SPI slaves don't support dynamic device discovery; some are even write-only or read-only. 

    SPI is widely used by microcontrollers to talk with sensors,  eeprom and flash memory, codecs and various other controller chips, analog to digital (and d-to-a) converters, and more.

    Blah, blah, blah ... yep, I'm sure Googling for "PCI digital to analog converter" would bring dividends. A good Googler is a valuable thing.

  • Sadoon Azizi added an answer:
    How to calculate the throughput of data center networks?

    I'm not sure about how the throughput in data center networks can be calculated.

    Could you please give me the exact formula that calculate the throughput of a data center network?

    Thanks in advance.

    Sadoon Azizi · Amirkabir University of Technology

    Dear Prof. Emre,

    Thank you very much for your help. It was useful to me.

    Dear friends, I think there is a different between the topology's throughput and routing algorithm's throughput. As far as I know, the second one is always less than or equal to the first one.

    According to the Dally's book (see its link at the end), the throughput of a network's topology is equal to:

    Bisection bandwidth / the half of network size.

    However, the throughput of a routing algorithm is different.  

    http://www.amazon.com/Principles-Practices-Interconnection-Networks-Architecture/dp/0122007514

  • Audrey Gendreau added an answer:
    How can I prove the improvement in energy consumption on any protocol in WSN?

    I would like to know what are the standards that should be used to compare between any protocol and improvement on this protocol in wireless sensor network.

    Audrey Gendreau · Saint Leo University

    Yes, I agree with Maria. However, you can keep it simple and just compute the amount of power consumed on a node by taking into consideration the traffic load and distance traveled of each packet. Keep deducting the power consumed to receive and send messages.  Once the simulation is over just deduct power consumed due to communication from the original amount on that node. In the end add all the remaining power left on each node to get the total network remaining power. The reason why you can do this is because communication costs are one of the biggest contributors to power consumption.

    The transmission of the power consumed in transmitting and receiving a k-bit message, a distance d (using this radio model), can be  computed as:

    E_Tx (k,d)=E_elec× k + ε_(amp )×k×(d)^2
      and
    E_Rx (k)=E_elec× k 

  • Love Kumar added an answer:
    Can I send a different TCP packet from 4 nodes to another in the same range to see the occurring collision and networks throughput by using OMNet++?

    See collision and throughput of network by OMnet++

    Love Kumar · Punjab Technical University

    one of my M.Tech student is wotking on OmNet++ ...for WSN ..What teh prob you r facing let me knw how cud i help you..

  • Rajkamal R added an answer:
    Which is the best simulation to simulate a wireless sensor network with smart grids in a home enviroment?

    I tried the Qualnet simulator but I don't know how to simulate smart grids such as PV

    Rajkamal R · Veltech Multi Tech Dr. Rangarajan Dr. Sakunthala Engineering College

    It is not possible to simulate Smart Grid with OMNET ++. WSN and Smart Grid has to be simulated separately. However MATLAB can be used to simulate smart gird aspects and little support to WSN simulations

  • Samaresh Bera added an answer:
    Can anyone help with the best simulator for hetNetwork for Demand Response (DR) in smart grids?

    Going to start simulating a model of DR. Any suggestion of best simulator, where it would be easy to simulate DR model with HetNet ....

    Samaresh Bera · IIT Kharagpur

    Yes, I have used it in my recent works. You can refer one of my papers: S. Misra, S. Bera, and T. Ojha, "D2P: Distributed Dynamic Pricing Policy in Smart Grid for PHEVs Management", IEEE Trans. on Parallel and Distributed Systems; in which we propose PHEVs' energy management in a dynamic pricing scenario.

    In order to support various networks (such as home area networks, WMN), NS3 is quite better among the network simulations (to me). I believe that you have preliminary concepts about NS3 (how it works, how to install different layered architecture). Once you have implemented your required network environment, then rest of things (mathematical calculations and your proposed algorithms) can be done easily.

  • Armin Simma added an answer:
    What are some open challenges in cloud security at SaaS and IaaS?
    I am willing to do work on cloud security issues at SaaS and IaaS. for the same. Can anyone suggest approaches and future scopes for this?
    Armin Simma · Fachhochschule Vorarlberg

    A "hot topic" in IaaS clouds is trust: How can the cloud customer trust the cloud provider? The easy - in my opinion solved - "problem" is: confidentiality of DATA sent to STORAGE clouds -> solution: just encrypt the data at the customer's site; then send it. Same with integrity of data sent to storage clouds: just add a default integrity technology (MAC oder digital signature): check it after receiving back the data from the cloud.

    The real problem (and thus) the hot topic is: How can the cloud customer trust the cloud provider when sending CODE to the cloud. We cannot just encrypt the code at the customer site. The provider must decrypt the code on his site -> the problem is: the provider has full insight (and control) of code sent to the cloud. This scenario is the normal scenario in many cloud environments: sending code (=virtual machines) to the provider or hosting (private) virtual machines that belong to the customer at the provider site. If you are interested in this topic see the slides of my talk I gave at ECCWS2014 and my paper.

    https://www.researchgate.net/publication/264338893_RetainingControlSimma_v6?ev=prf_pub

    https://www.researchgate.net/publication/264037748_Retaining_Control_Over_Private_Virtual_Machines_Hosted_by_a_Cloud_Provider

  • Kumar Saurav added an answer:
    How do I implement a LEACH protocol on OPNET modeler?
    Or If any one has C or C++ codes on LEACH they should help me. I have a project working on based energy performance analysis on WSns, that has to do LEACH cluster protocol. It will be good for me if anyone can enlighten me on how to simulate the LEACH routing protocol on OPNET simulator or send me C or C++ codes on LEACH.
    Kumar Saurav · IIT Kharagpur

    Source code for leach is available at http://tetcos.com/blog/2014/01/28/wsn-leach-protocol-user-contributed-code/

  • Runa Barik asked a question:
    Can we use plant Environment as a backbone for Internet?
    • To design a sustainable Internet --- Reliable, cost-effective, green-communication, heterogenous backbone
  • Raghu Balimallur Ramappa added an answer:
    How can I overcome DDOS threat in DATA center networks?
    w.r.t. above topic, can DDOS in an application layer be overcome by using ANN methodology or the Genetic Algorithm approach?
    Raghu Balimallur Ramappa · Bapuji Institute Of Engineering & Technology, VTU
    I am thank full to your reply on the query i had posted and i will definitely be a part of your work on contrary i am in between beginner and intermediary stage of my work .
  • Dawei Li added an answer:
    Has anyone used an NS3 simulator? Since it lacks a switch module, how should we model a switched Ethernet?
    Some works used the bridge module and the CSMA channel, but I don't think the modeling is appropriate for a switched Ethernet.
    Dawei Li · Temple University
    Thank you so much!
  • Grant Mackey added an answer:
    Which simulator is suitable for simulating the topology of data center networks?
    There are many simulators (eg: DCNSim, NS3) to simulate the architecture of data center networks. Which one is more powerful and provide good flexibility?
    Grant Mackey · University of Central Florida
    You can also look at omnet++ or the structural simulation toolkit.

    It really depends on how accurate you need to be versus how rapidly you wish to prototype something.
  • Virendra Yadav added an answer:
    For ns2, which version of linux can I use to facilitate the manipulation of ns2?
    Because of the existence of many operating systems in linux, I can't decide alone, so please help me. My processor is the intel(R) pentium(R)Dual CPU T 2310 @ 1.46GHz 1.47 GHz.
    Virendra Yadav · ABES Engineering College
    you can use linux mint or Ubuntu
    just type sudo apt-get install NS2
    after that sudo apt-get install x graph
  • Djamel Teguig added an answer:
    Is there any research going on regarding cyclostationary spectrum sensing methods for more simple computational methods?
    Spectrum sensing
    Djamel Teguig · Royal Military Academy
    Dear sir
    In this paper a simple cyclostationary spectrum sensing method is proposed, it can be usefull. For implementation, I can help you

    "Multi-cycle Cyclostationary based Spectrum Sensing Algorithm for OFDM Signals with Noise Uncertainty in Cognitive Radio Networks"
  • Abhishek Dwaraki added an answer:
    Is an Erdos-Renyi Communication network possible?
    We know very well that a communication network is always assumed to be or also exhibits the nature of Scale Free Networks. But is it possible that a communication network can be framed as ER Network or a Random Network?
    Links to any papers or thesis that model communication networks as ER or Random model would help too.
    Abhishek Dwaraki · University of Massachusetts Amherst
    I think this might shed some useful information on whether networks can be modeled on the Erdos-Renyi model and can be scale free or not. It is basically a review paper, but has some interesting points that can be made use of.
  • Peter T Breuer added an answer:
    Which is the best platform to install NS2 on Linux?
    I have to simulate DCCP and UDP on NS2 , for my presentation and showing the differences in throughput, delay, and jitter. I want to know that NS 2.35 standalone supports DCCP simulation, do I have to write any code for this simulation?
    I am new to NS2 n linux platform.
    Help is appreciated.
    Peter T Breuer · Birmingham City University
    A "plot form" is? The dependencies on debian for ns2 v2.35 are

    --- libc6 (>= 2.4)
    --- libgcc1 (>= 1:4.1.1)
    --- libotcl1 (>= 1.14)
    --- libpcap0.8 (>= 0.9.8)
    --- libstdc++6 (>= 4.6)
    --- libtclcl1 (>= 1.20)
    --- libx11-6
    --- libxext6
    --- tcl8.5 (>= 8.5.0)
    --- tk8.5 (>= 8.5.0)

    so no, "xgraph" is not required. It's self-contained. I note that debian _suggests_

    --- gnuplot

    which is a hint that graphs will be produced and if you want to display them a graph displayer is required. Gnuplot does that. I think "xgraph" is an older and simpler independent alternative from way back, possibly replaced by "ygraph" nowadays. But gnuplot is standard and reliable.

    Gnuplot reads gnuplot source code, so ns2 must be capable of producing it! I don't know what xgraph reads, but presumably ns2 also has a driver for it.
  • Admin Mycolleagues added an answer:
    Could anyone present some information, survey, mechanisms about SDN (Software Defined Networking) applied to cloud computing?
    As elastic cloud architectures and dynamic resource allocation evolve and as mobile computer operating systems and virtual machines usage grows, the need has arisen for an additional layer of software-defined networking (SDN). Such a layer allows network operators to specify network services, without coupling these specifications with network interfaces. This enables entities to move between interfaces without changing identities or violating specifications. It can also simplify network operations, where global definitions per identity do not have to be matched to each and every interface location. Such a layer can also reset some of the complexity build-up in network elements by decoupling identity and flow-specific control logic from basic topology-based forwarding, bridging, and routing.

    From http://en.wikipedia.org/wiki/Software-defined_networking
    Admin Mycolleagues · Federal University of Santa Catarina
    Please see a survey at:

    http://cloudcomputing.ieee.org/features/pdf/net_virt.pdf

    Abstract:
    Network virtualization is the key to the cur- rent and future success of cloud computing. In this article, we explain key reasons for virtualiza- tion and briefly explain several of the networking technologies that have been developed recently or are being developed in various standards bod- ies. In particular, we explain software defined networking, which is the key to network pro- grammability. We also illustrate SDN’s applica- bility with our own research on OpenADN — application delivery in a multi-cloud environ- ment.
  • Radoslav Dejanovic added an answer:
    Does anyone have extensive knowledge on prior art in the field of computer networking virus?
    .
    If you're looking after the first virus ever that spread in the wild, that would be Elk Cloner:

    http://en.wikipedia.org/wiki/Elk_Cloner
  • Sarmad Abdulazeez asked a question:
    Is there anyone have worked at Oversim and Omnet++?
    I need to know how to start simulate at oversim and Omnet++
  • Faiza Al-Salti asked a question:
    Can anyone help with a problem in simulation via Aqua-sim?
    I'm trying to implement a routing protocol in the aqua-sim simulator. However, I have a problem when I run the tcl file. The nodes are given the same XYZ positions as the first node, although I initialized them to different values in the tcl file.

    Can any one suggest what might be the cause of this problem, please?
  • Ahmad Kamal Ramli added an answer:
    How will the future internet be?
    People in US and EU trying to pass the net neutrality. Internet with all packets treated equally. No privileges and tier design. Is it good or is it bad to internet architecture?
    Ahmad Kamal Ramli · University of Leeds
    thanks for the reply . Since now as the internet user we are using TCP IP and on the other hand some other protocols also running but more on privileges mode.
  • Kayode Eluwole asked a question:
    What are the main distinguishing qualities of heterogeneous cellular networks?
    Femto and Pico eNBs are some of the commonly adopted HetNets. Their deployment in the traditional macro base stations is meant to increase capacity to proffer solution to increasing demands for data but these solutions in turn pose greater a problem of interference. If they are important to be adopted why is this so?
  • Mrs. Mina Mishra added an answer:
    Is it possible to do handoff between WiFi and WiMAX?
    When the user move from one place to another, if the received signal strength(RSS) is lost or for QoS requirement is it possible to handoff the channel from WiFi network to WiMAX.
    Mrs. Mina Mishra · Christian College of Engineering & Technology
    Yes, certainly it is possible we can find research papers based on the topic . Moreover software has also been developed.
  • Osama M. Hussain Rehman added an answer:
    Can anyone answer my question on a signal's direction of arrival in VANETs?
    In VANETs we read a lot about classifying the packets arriving at vehicles as being either arrived from "vehicles at the front" or from "vehicles at the back". However, I am interested to know about the theory behind the detection of a signal's direction of arrival in VANETs. What equipment is used in that? Do positioning devices such as GPS or GNSS modules play a major role, and what is the theory behind it?
    Osama M. Hussain Rehman · Sultan Qaboos University
    Thank you Daniel. You are right, with the inclusion of positioning support using GPS or GNSS enabled modules, we should be able to find the vehicles absolute position, direction of vehicles movement, speed (In stand alone mode, i.e. in each car).

    If the positions are shred among vehicles, then distance between them can be found as well. However, i think GIS maps (along with parameters mentioned above) would also play a role in finding the relative position of vehicle from one another in a specific road segment.

    Regards,

About Computer Communications (Networks)

A computer network is a collection of computers and other hardware components interconnected by communication channels that allow sharing of resources and information.

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