Wireless Computing - Science topic

To do research in wireless, computer networking, and the generation of mobile networks, you will need a strong foundation in the following skills:

In addition to these core skills, it is also beneficial to have experience with the following:

Finally, it is important to be able to think critically and creatively, and to be able to communicate your ideas effectively to others.

Here are some specific examples of research topics in wireless, computer networking, and the generation of mobile networks:

If you are interested in pursuing a career in research in wireless, computer networking, and the generation of mobile networks, I encourage you to develop the skills listed above and to explore the research topics that interest you most.

Currently, the FCC is actioning spectrum in the 27.5 GHz to 28.35 GHz, 24.25 GHz to 24.45 GHz, and 24.75 GHz 25.25 GHz, range for millimeter-wave 5G use. The FCC may also be considering opening 3.7 GHz to 4.2 GHz mid-band frequencies for 5G, and may also be considering opening 4.9 GHz public safety bands for 5G access.

Himadri Nath Saha, it seems to be a fascinating motivation scenario. The investments and the continuous growth of streaming games have imposed new requirements of response time (i.e., ultra-low latency). I am looking for DSP systems where latency-sensitive applications can be easily deployed on geo-distributed constrained resources avoiding creating a multi-tier of components.

Dear Anik,

I suggest you to see links and attached files on topic.

Paper Title (use style: paper title) - laccei

Survey on Unmanned Aerial Vehicle Networks: A Cyber ... - arXiv

Survey of Important Issues in UAV Communications Networks - arXiv

Best regards

Dear Anik Islam Abhi,

this is "transfer / transmission time". I would use the following terms:

Transmission over a data link: transmission time; packet / data transmission time; (mean) packet / data transmission time

(mean => variable packet / data length)

When transmission over multiple data links (delays in nodes) I would use the terms: transfer time; packet/data transfer time; (mean) packet/data transfer time

Best regards

Anatol Badach

I think spectrum access protocol is a special case of medium access protocol. Medium access protocol can be accomplished also by time division multiple accessing, code division multiple accessing, space division multiple accessing and frequency division multiple accessing which is spectrum access protocol.

Best wishes

Solar Powered Cellular Networks

[1] A. Jahid, A. B. Shams, and M. F. Hossain, "PV Powered CoMP based Green Cellular Networks with Standby Grid Supply." International Journal of Photoenergy 2017(8) · February 2017

Link: https://www.researchgate.net/publication/313840103_PV_Powered_CoMP_based_Green_Cellular_Networks_with_Standby_Grid_Supply

[2] A. Jahid, A. B. Shams, and M. F. Hossain, "Energy Efficiency of JT CoMP Based Green Powered LTE-A Cellular Networks." International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET 2017), Chennai, India - March 2017.

Link: https://www.researchgate.net/publication/313421109_Energy_Efficiency_of_JT_CoMP_Based_Green_Powered_LTE-A_Cellular_Networks

[3] A. B. Shams, A. Jahid, and M. F. Hossain, "A CoMP based LTE-A simulator for Green Communications." International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET 2017), Chennai, India - March 2017.

Link: https://www.researchgate.net/publication/313861444_A_CoMP_based_LTE-A_simulator_for_Green_Communications

[4] A. Jahid, A. B. Shams, and M. F. Hossain, "Energy Cooperation among BS with Hybrid Power Supply for DPS CoMP Based Cellular Networks." 2nd International Conference on Electrical, Computer & Telecommunication Engineering (ICECTE), Rajshahi University of Engineering & Technology (RUET), Bangladesh, December 2016.

Link: https://www.researchgate.net/publication/310166355_Energy_Cooperation_among_BS_with_Hybrid_Power_Supply_for_DPS_CoMP_Based_Cellular_Networks

Dear Choi,

You can make a survey on previous research articles related to S-ALOHA and review CDM-based results and discussion. 

The standard data rate of 1 Mbps and ( cough! ) "enhanced" data rate of 2Mbps is pretty much what you have to work with.  The high speed devices are still fairly expensive and uncommon, as you mention, those get you to 25Mbps.    That is the native symbol rate.  So not much to "fix" there.

As for Bluetooth cutting out?  That's not a feature of Bluetooth, it could be a number of factors specific to your use case: drivers, RF environment, the transport methods, the computing devices.  I consider that not to be an intrinsic Bluetooth issue.   For synchronous transfer near maximum throughput, you do not have an throughput to retry lost block because the aggregate of valid and retried data exceeds the available throughput.   So you cannot run at 1Mbps, as there is no room for errors.   The strategy is to reduce the bulk of the data, leaving ample headroom.

For asynchronous data transmission, you need s TCP-like transport mechanism.  Heck, even things like Z-Modem does a block integrity check and re-transmission, is appropriate.

Another factor is the RF space.   Bluetooth devices come in 3 distance ranges - in some cases the only difference is the type of antenna in the device.   The maximum range of 100 meters is achievable.   Its also possible to attach yagi antennas to bluetooth interfaces dramatically extend the range.   I have, myself, sent bluetooth over 500 meters with very cheap yagis.  You can even do this with low power devices.  More gain is always better,

The point of the above paragraph is that if you improve the gain of the antennas, you can have much more immunity to ambient RF.   Improving the SNR will help increase the throughout.

Hope that helps.

Ok thanks a lot

I would answer yes, if the femtocell is being used outdoors, and you are looking for seamless coverage between femtocells. But frequently, femtocells are used to improve indoor coverage, without offloading to WiFi. So in this case, the femtocell coverage is more or less confined to inside the building.

(Parenthetical editorial comment: While in principle, femtocells are the natural progression of the cellular model, to reuse spectrum even more effectively, some of the interest in femtocells is tied to LTE-U. This is where the cellular service gets to grab free, unlicensed spectrum, the same spectrum used by WiFi, to sell revenue-making cellular service. If you offload to WiFi, instead, the cell company does not make revenue from those sessions.)

No, when the packets are in the buffer, you should be able to treat them differently based on different criteria, e.g., priority. It depends on the implementation.

Try this PDF on Stieljest and related transform. If people are interested in pusuing this further, please let me know, yangbrookchen@yahoo.co.uk. I find yahoo easier to handle.

Yang

There is a huge literature on k-node connected and k-edge connected networks, network loading, network design, networks with bounded rings, etc. Try looking at past issues of the journal "Networks".

Sure its feasible. You can achieve lots of capacity, when using optical frequencies, simply because you're so high up in the spectrum. A tiny sliver of spectrum has huge potential, because that tiny sliver can be a lot wider, in terms of Hz of bandwidth, than anything remotely feasible in the radio frequency bands.

The problem will be obstructions, though, because light won't diffract around obstacles as radio frequencies do. So range will be limited. Can't cover an entire house with just one access point, as you can with WiFi. Can't go through bad weather as you can with radio, either.

The irony in this is that modulating light, incoherent light such as that used in VLC, is really primitive stuff. Because the source is incoherent, you're limited to using either on-off keying (like Morse code) or intensity modulation (like AM radio). The huge capacity is possible regardless, but the modulation techniques are definitely early 20th century!

You need to  establish what sensor are you going to use, because you could possible find some sensor that can use some standard automation protocol, such as Hart, Modbus, Fielbus, with these information you can look for some API implementation of your field protocol. I think that there are some API of Modbus in Java ( http://stackoverflow.com/questions/4689381/need-modbus-java-library )

Hi Fabio, 

Please look at the LTE 36.141 specification document 

Here, under section 5.7, you see the LTE carrier frequency assignment

Also, what do you mean "can there be more interference?" ? 

Regards

Ramesh

This is the best reference for that:

The previous answer is great and gives some good examples. Another "reason" for ILP that I might add is that it is often the most obvious and most straightforward way to represent the selection of discrete alternatives (for example a binary variable X_ j is 1 or 0). I'd even ask what would you do instead? Perhaps represent X_ j as a real number bounded by 1 and zero (relaxation of the problem). This is a strategy for attacking the case, but you would have to agree that fractional solutions are not representative of the real problem that we have set. (This occurs in facility location, portfolio selection, and many other areas.) So the problem might require branch and bound or other implicit enumeration schemes to finish off the selection of only integer solutions.

I think that if you want to understand some of the beauty (and difficulty) of ILP check out the knapsack problem. Almost as simple as you could imagine, and yet there are integer variables with real meaning and significance for this model. While this is "difficult" it has not stopped clever algorithmic approaches that improve over the most obvious greedy heuristic.

Dear Amr,

I would propose the following procedure:

- From the filter requirement, determine the filter function and the order of the filter.

for example as in your question, Chebychev, fourth order.

Then you can get H(s) of the filter as H(s) = 1/ D(s),

where the denominator polynomial coefficients are known

Then you propose the circuit for the implementation, which in your case is a passive network composed of L and C elements.. Then you derive the transfer characteristics of this circuit by means of circuit analysis, say Hi(s), putting it in the form of H(s).

By equating the corresponding coefficients of of the denominator of both responses we get a number of algebraic equations equals the number of unknowns which are the element values of the circuit.

You can solve these equations using Matlab.

The source and load resistances may be Tartary chosen. eg RS=0 and RL=infinity. 

You can compare your results with published results. Please follow the appendix of the boo having the web address:197.14.51.10:81/pmb/TELECOMMUNICATION/digital_filter_design.pdf

you can use fazzy logic or automata  for select best decide  for your network ;

for example fuzzy help you consider several parameters and select best decide base this parameters 

or you can use automata for determinat state probability for next dicide 

best regard ..

If this is your research problem, then you need to figure out ways yourself. Or, you use Hadoop's :

Each packet should have a field called Priority and composed of 3 bits. So, priority varies from 0 to 7 (respectivelly, from 000 to 111, in binary). Hence, the receiver node will compare its own priority to the received packet, such that the highest priority is 0.

If its priority is higer than the one of the received packet, then, it can ignore the received packet and send its own packet.

So, in emergency case, the node wishing to send must set its priority field to 0.

Of course, if you want to increase the priority levels according to the network density, you can add of PRIORITY field having more than 3 bits.

Hope this will help.

You can use the attached MATLAB which is supported by the ns-3 developers for simulating small scale fading in LTE according to the 3GPP documentations:https://www.nsnam.org/docs/release/3.21/models/html/lte-user.html

The size of packet depends on the application as well as the protocol. Time slot based scheduling is taken care by MAC layer and not the routing protocol. Routing protocols determine the packet structure for data as well as route maintenance. number of packets at source network layer and receiver network layer can be counted to determine packet delivery

 What about the fading model

Or maybe you can use multiple instances of iPerf to mimic different traffic types. Suppose that in Scenario 2 you create an iPerf instance in a station using UDP and certain bandwidth; another instance using TCP at another bandwidth and so on for as many Access Categories/Traffic Types as you want. This way you get the aggregate throughput from each iPerf instance and compare it to those achieved in Scenario 1 using the same tools (but instead of instances you run a single iPerf process in each station, of course).

In principle, why not?

Walkie talkies typically operate either in the citizens band, high HF, or in the VHF spectrum. Whereas mobile phones operate at high UHF, above 700 MHz to the GHz ranges. So that's one problem. The antenna requirements, for small hand held devices with no external antenna, would make use walkie talkie frequencies quite inefficient.

But mobile phones are already multiband devices, after all, so why not (in principle)? Mobile phones already detect frequencies available at any given location, and pick the best one to use. So I don't think there's anything intrinsically impossible about designing a "mobile phone" to use other frequency bands than those allocated to cellular. However, the spectrum allocation authority in your country would most likely not allow this.

Yes zigbee is one way to go as mentioned

Thank you Jose and Alessandro.

Dear P. Prakasam,

Lifetime of the sensors in WSN be improved can be improved by two ways:

1. By saving its transmission energy and 2. By saving its processing energy

(With the efficient use of aggregation and routing protocols and data compression techniques may also be used to reduce the size of data, etc.)

You can use NS3, MATLAB (Simulink) or OPNet.

@diamel teguig sir thnks for your view on it..

@muhammad naveed-sir How to determine the weight of a link in wireless mesh network and what are the criteria which kept in mind before allotting or assigning  weights to it..

I used Mosync "http://www.mosync.com" for building couple of applications and you can simply use JQuery mobile within Mosync to create whatever applicaitons you would like to create. You can use any webservice and call it with ajax from your JQMobile pages to interact with your server. So all what you need to do is:

1. Learn JQMobile

2. Learn Ajax calls

3. Have a web service that controls and interacts with your database and code. (I personally use web2py framework as a server and write my controllers with python).

4. Create a hybrid application or an HTML5 application inside mosync and start adding JQMobile pages inside it and call your web services using ajax.

5. Build to any platform.

6. Test your project either on the web, phone emulator or connect your phone to your computer and test it.

Let me know if you need any more information.

My dear @Shrikant, the following US patent Hybrid bluetooth/RFID based real time location tracking US 6717516 B2 may be the solution to your need!

We can also use Geometric Mean Decomposition (GMD) for  precoding. The GMD composite the channel into subchannels with equal SNR.

WMAN enables the users to create wireless connections between multiple locations within a metropolitan area. It connects the multiple office buildings in a city or on a university campus. WMAN does not require high cost of placing fiber or copper cabling and leasing lines. Further, WMAN can work as backups for wired networks.

WMAN uses either infrared light or radio waves to transfer data. WMAN is supported with three different standards.

• 802.16

• HiperMAN

• HiperACCESS

In addition, Back haul and last mile are two fundamental types of WMAN.

The advantage of MWAN for implementing metropolitan area network is its beauty due to less cost than fiber-based Local area networks (LANs) due to several reasons. It is easy to use, extend, exchange or back up prevailing fiber infrastructure within hours, preserving time and money on personnel. It also eradicates leased line costs, fiber trenching cost in laying fiber. Another noteworthy benefit of implementing the WMAN is to bridge the “digital divide” by affording linking communities that have not had the access to wireless internet connections and LAN. Implementing of WMAN allows companies, government agencies, etc. to swiftly increase their internet service into new marketplaces for generating better revenues. From other side, WMAN has security issue because it consists of large area and having problem being hacked the information. A WMAN is merely a bigger WAN track, and thus provides the larger chance for a hacker.

Dear dr. Ismat,

It seems that the orthogonal frequency division multiplexing and multiple accessing is the most suitable modulation technique for the wide band communication systems either wireless or wired. Compared to single carrier system, it has many advantages especially the inter symbol interference in multipath channels. OFMD has more immunity against multipath effects. OFDM is more easier to implement and equalize. It is also more robust against deep frequency selective fading. Compared to FDM it is more band width efficient since the subcarriers are allowed to overlap as they are orthogonal by making their frequency is an integral multiple of the inverse of the symbol time.. Every carrier is M-QAM modulated according to the available signal to noise ratio. So, the bandwidth efficiency can be increased for higher signal to noise ratio.Consequently, one can make full use of the channel conditions to increase the bandwidth efficiency and increase the bit rate of the communication system.

It out performs the wideband code divination multiplex accessing as it has a higher bandwidth efficiency and easier to control than the spread spectrum in WCDMA. Time division multiplexing is used with single carrier systems which outlined at the beginning of the comment.

The OFDM sums many advantages against the other modulation and multiple accessing techniques more than its drawbacks.

The drawbacks are the high peak to average power ratio which makes the power amplifier expensive and more power hungry. The other drawback is the intercarrier interference. But there are powerful techniques to mitigate these draw backs.

In the foreseen future, OFDM may remain the most preferable modulation and multiple accessing technique. It is even the recommended modulation technique for the ultrawideband UWB communication systems.

Could you please provide the necessary steps?

You should uses NS3, it supports b/g/e/n/a (n only siso)

Thanks for your answer. My question was more inclined towards Wired and Wireless LAN (Wi-Fi) Site Surveying, in computers.

You can try to implement

COngestion Detection and Avoidance (CODA) approach described by Wan et al.

I am not sure about how to exactly implement in opnet. You need check the opnet developer manual specifying that how to incorporate your own protocols or something like that.

Another way is to use Castalia network simulatior which is specifically designed for WSN, while openet is general purpose and also not free.

Dear Wenjie Yu, Hopefully, you will get some knowledge related to your question. The article is accessible via link given below.

Frequency ranges mostly consist of two frequency bands. One half of the frequency band, called the uplink, is used to transmit data from the mobile phone to the base station. The other half of the frequency band, called the downlink, is used to transmit data from the base station to the mobile phone.