Mobile Communications - Science topic

I have also the same problem. please help me how to solve this.

The 6G communication network aims to integrate terrestrial, aerial, and maritime communications into a robust network. Although still in its early stages, the research community actively explores new and exciting possibilities. One focus application is leveraging AI and ML for intelligent network management and optimization. It is also worth to explore Quantum Communication and Quantum Machine Learning techniques to enhance communication capabilities. Additionally, Blockchain technology plays a crucial role in improving security, privacy, and trust within 6G networks. Another key research area could be enabling high-frequency, high-bandwidth communication using Terahertz and Millimeter Waves. In the context of 6G, location-based services and applications are also crucial. Research areas related to location-based services include precise positioning, privacy mechanisms, context-aware networking, environmental monitoring, and geospatial data fusion. These are some of the research areas worth exploring in the future.

Christian H.

The performance of 5G campus networks, especially in a standalone (SA) configuration, can vary widely depending on various factors, including settings, configurations, hardware, deployment environment, and network design. Achieving the advertised numbers of up to 1 Gbit/s in both uplink and downlink with latency below 5ms is theoretically possible under ideal conditions, but it's not always a reality in real-world deployments. Here are some insights into why you might see variations in performance:

1. Deployment Environment: The physical environment in which the network is deployed can significantly affect performance. Factors like interference, signal propagation, and obstacles can impact signal quality and, consequently, data rates.

2. Network Configuration: The configuration of the 5G network, including the choice of frequency bands, spectrum allocation, and antenna placement, can influence performance. Some frequencies offer higher bandwidth but shorter range, while others provide better coverage.

3. Network Load: Network performance can vary depending on the number of connected devices and the data traffic they generate. High network congestion can lead to reduced data rates.

4. Hardware and Infrastructure: The quality of the network infrastructure, including base stations and user equipment, can impact performance. High-end equipment may achieve better speeds than lower-end alternatives.

5. Application and Use Case: The specific use case and applications running on the network can affect performance requirements. Some applications may be more sensitive to latency and require higher data rates than others.

6. Research Methodology: When interpreting research papers, it's essential to consider the methodology used in the experiments. Factors such as the number of test scenarios, equipment used, and environmental conditions can lead to variations in reported results.

7. Time and Evolution: The performance of 5G networks can improve over time as operators optimize their networks and roll out software updates. Early deployments may not reach the same performance levels as mature deployments.

Given these factors, it's not surprising to see variations in the reported performance of 5G campus networks. It's essential to consider the context and conditions under which the measurements were taken when evaluating research papers. Additionally, performance may vary from one campus network to another based on specific deployment choices and objectives.

If you're working on 5G campus network research, conducting your own field tests and measurements in your specific deployment scenario can provide valuable insights into the network's performance and help validate or refine the published results.

enclosed research article may help u

There are various ways in which cryptography can be applied to value-added services in mobile networks. One way is to use encryption to secure the communication between the mobile device and the service provider. This can be done by using algorithms such as AES (Advanced Encryption Standard) or RSA (Rivest–Shamir–Adleman).

Another way is to use digital signatures to authenticate users and transactions. Digital signatures use a combination of public and private keys to prove the authenticity of a message or transaction. This can be particularly important for financial transactions or other sensitive transactions.

Finally, it's important to use secure protocols such as TLS (Transport Layer Security) or HTTPS (HTTP Secure) to ensure that all communication between the mobile device and the service provider is encrypted and secure. These protocols can help to prevent eavesdropping and other types of attacks that can compromise the security of value-added services in mobile networks.

1. Encryption of data: Data encryption is the process of transforming data into a form that is difficult or impossible to decipher, making it unreadable to anyone except those who possess the correct encryption key. This can be accomplished through the use of strong encryption algorithms such as AES, RSA, and 3DES.

2. Multi-factor authentication: Multi-factor authentication (MFA) is an authentication process that requires two or more factors such as a username, password, and fingerprint scan or facial recognition to verify identity. By using MFA, organizations can significantly reduce the risk of unauthorized access and protect sensitive data.

3. Mobile device management: Mobile device management (MDM) is a set of tools and processes used to secure and manage mobile devices. MDM can provide remote device management, including the ability to remotely lock, wipe, or locate a device.

4. Secure cloud storage: Cloud storage solutions such as Google Drive, Dropbox, and iCloud offer secure storage of data, ensuring that only authorized users can access it. These solutions encrypt data both in transit and at rest, helping protect it from unauthorized access.

5. Virtual private networks: Virtual private networks (VPNs) are used to securely connect two or more devices over the internet, allowing them to communicate with each other securely. A VPN encrypts all data in transit, helping protect it from interception.

6. Two-factor authentication: Two-factor authentication (2FA) is an authentication process that requires users to provide two pieces of evidence in order to gain access, such as a username, password, and one-time code generated by a mobile app or device. This helps protect against unauthorized access and malicious actors.

I suppose this depends on what kind of obstacles you are considering and how they are affecting the signals. If you consider an object that is scattering the signal, then the pathloss will be proportional to (d_1*d_2)^2 where d_1 is the distance from the transmitter to the obstacle and d_2 is the distance from the obstacle to receiver. For a given total propagation distance d_1+d_2, it follows that the pathloss is at its smallest when the scattering object is close to the transmitter or the receiver.

You can down load the several software like net monitor in your mobile and you can check the network health ' data rate (TX and rx) tower id, RSSI ' signal to noise ratio etc in stationary as well as in state of mobility .G-net is also useful for primary investigation respective to the different channel ( BCCH' TCH ETC).

As many as four in 10 UK PhD students may be at “high risk” of suicide, according to a study that underlines the chronic levels of stress among doctoral candidates...

Loneliness and intellectual insecurity highlighted as prime reasons for elevated suicide risk among doctoral researchers...

Dear Yukinari He ,

It would be nice from you that you define the relation between the communication symbols and numerology??

This is the first time that I hear from such vocabulary in electrical communication systems.

What I know is the different symbols resulting after modulating the binary data.

There are binary symbol where every symbol contains either binary 0 or 1.

There is the the 2-bit symbol representing values from 00,10,01 and 11.

There is 3-bit symbol which has 8 states.

and so on.

This method of M-ary symbols help control the number of bit hertz.

And one can send more data in the same bandwidth by using higher order modulation.

It is known that every channel condition or S/N ratio can allow specific symbols.

If it mean symbols then yes one can control the order of modulation of the symbol.

Best wishes

What i can’t understundom you Kenechukwu Emmanuel Umeh

Wireless technology changes gradually, because the demand for data services and quality-of-service are changing gradually. However, there is hope that 5G will enable a paradigm shift, in the sense of supporting the digitalization of our world. So 10 years from now, when we look back and compare 2021 and 2031, the belief is that 5G will have contributed to radical changes in how vehicles, IoT devices, factories, and work places are now wirelessly connected and support stringent service requirements.

It is generally hard find closed-form expressions. It always the same math involved:

Say that the SINR is S/(I+sigma^2), where S and I are random due to fading. Then the outage probability when communicating at the rate x is:

Pr{ log2(1+S/(I+sigma^2)) < x } = Pr{ S/(I+sigma^2) < 2^x - 1 }.

If you know the distribution of S/(I+sigma^2), then you can compute this directly.

If you only know the PDFs of S and I individually, then you need to rewrite it as

Pr{ S/(I+sigma^2) < 2^x - 1 } = Pr{ S - I (2^x - 1) < sigma^2 (2^x - 1) }.

Now "sigma^2 (2^x - 1)" is a constant, but you need to compute the PDF of "S - I (2^x - 1)", which can be done via integration. The joint PDF of the sum of random variables is obtained by convolution.

At the end of the day, the chance that you get a nice PDF of "S - I (2^x - 1)" so that you then compute the probability is closed form by integration over the PDF from 0 to sigma^2 (2^x - 1) is not so big.

Dear Omar ALzoubi ,

welcome!

peace upon you!

My opinion is that these functions are physical functions and not only a mathematical or statistical instructs.

The white noise is generated naturally in resistive and electronic devices and circuits. They appear always as an annoying signal to the useful signal.

Such noise signals are characterized by Gaussian distribution and in the frequency domain they appear as a consatnt spectral power density eqaul to kT.

So, what is the motivation to get an equivalent! What is meant by equivalent distribution!

May be important as the additive white Gaussian Noise is the channel fading and how it attenuates the signal randomly in spatially and temporarily. The probability density function of the signal amplitude follows two models the Rician channel model and the Rayleigh model. While the Rician model has a line of sight components the Rayleigh model assumes complete scattering of the signal.

There are also practical wireless channel models for different environment

Best wishes

Hi!

A good understanding of linear algebra and probability theory is necessary to do good research in this field. If you want examples of how to transfer equations into simulations, you can have a look at my book and the accompanying code:

Species don't evolve that fast, they don't evolve from one generation to the next. However, it is only technological progress that is so dynamic and causes changes in people's behavior, e.g. in terms of the dominant communication standards. Communication is becoming more and more remote, realized via the Internet. In addition, the SARS-CoV-2 (Covid-19) coronavirus pandemic accelerated the processes of digitization and internetization of many spheres of human activity. But it is still the same species of Homo sapiens.

Best wishes,

Dariusz Prokopowicz

hi Orogun Okunola Adebola , 5G brings high speed, not all the time needed , but in IoT standardization 5G offers a best deployment solution for Smart city , self-drive cars, E-commerce an a lot of future solutions.

The highest speed of the user during the communication session is determined by the maximum allowed doppler shift variations as the Doppler shift causes fast fading in the channel. This fast fading can be equalized up to some extent and so one has to limit speed of the vehicles to make the distortion affordable and the quality of service acceptable.

Best wishes

Thank you for all the answers. I will read through the materials.

You can use active divider composed of emitter follower or source follower transistors connected in parallel. Every emitter follower has matching function to transform 50 ohm output resistance to 50 x16=800 ohm.

This will be a very wide band divider consisting of 16 emitter followers connected in parallel. The input will be capacitively coupled.

Best wishes

The device senses the electromagnetic radiation by an antenna and amplifies it by a wideband low noise amplifier and then a fast Fourier transform to analyse the frequency spectrum and display it on a screen. It can acquire the field strength in a real time as the stated in Data sheet.

Since it is a wide band electromagnetic sensor one must turn off all interfering sources as the instrument will sense it.

For more information please follow the pdf: http://www.testequipmenthq.com/datasheets/NARDA-SRM-3006-Datasheet.pdf

We mad a similar set up to sense the EM radiation:

I would like to bring some clarification here.

There are at least two layers for communication:

-service layer, including user interface

-network layer, including infrastructure

One to one communication at service level will always exist.

One to one "cabling" has been removed in the early days of telephony by switching. A switch is a matrix n x m: n input, m outputs. Calling party 2 can be connected through the switch to receiving party 21...

You had manual switch (telephone ladies in the past, that was discrimination...) then electrical switch (cross bar) and electronic switching. This is why telephone exchanges were large building and are now a chip...

You can add cherries on the cake, but that's what you have inside.

Now you have the social preferences at play: one to one, one to many, many to one, etc...

Group communication, private one to one exchange...

Humans always add features, and rarely suppress any of what they have.

A comprehensive survey on D2D communications, covering different aspects related to modeling, mobility management, and applications can be found here:

Article A Survey of Device-to-Device Communications: Research Issues...

image/video compression is necessary because of transfer on network from cloud/server to client, fast loading in web pages, and save storage

Dear Abdullah,

welcome,

There are some methods to reduce the peak to average power ratio of the OFDM signal to lower their dynamic range during transmission needing smaller power amplifier. If you go to my research page you will find most of the methods used for this purpose: https://www.researchgate.net/profile/Abdelhalim_Zekry/research

Best wishes

Carrier Aggregation, Massive Connections, 3D Beamforming; IoT; M2M; MIMO 128TRx

I think its not related to satellites but depends up on the signal booster network by cellular companies.

I am for agenda media, for experience suggests that they use lots of different social media already, and for slightly different purposes--some for peer-to-peer networking more information sugest.

The link given by Dr Arvind Singh is extremely relevant

Dear Omniea,

welcome,

May be the major effort must be directed to reduce the radio frequency dose incident on the body of a human. This can be accomplished by reducing the power of the source of such radiation. This a matter of the communication system design issues. I do not know whether you are a communication engineer of which is your specialization. There are some methods to reduce the radiated power from the base stations while keeping the achieved data rate constant. The most effective method is using MIMO systems.

The other solution may be to decrease the area covered by every base sations. this will reduce much the power radiated since the distance is proportional to square root of the power.

May be one of the most serious sources are the mobile terminals themselves as most of them are handheld. especially when one makes a talk.

There are some precautions that one uses to reduce his subjection to the rf radiation as to communicate hand free through blue tooth devices.

The other issue is the biological effects of such radiation on human tissues. There are many studies on such biological effects of the rf radiation on the human body.

Best wishes

The "only" reason to go up in frequency is to have access to more bandwidth. More bandwidth also requires higher sampling rate and higher frequencies require transmitter and receivers that are capable of modulating signals of that kind.

Visible light is one example of terahertz signals. Just as visible light is blocked walls and other objects, terahertz applications will be limited in the same way.

Hello Samuel Lakew

I rally liked your description of the expected disastrous effects of 5G, and I asked Dr. Ted Rappaport (one of pioneering professors from the NYU in the field of mmWave and 5G) about the health effects resulted from using such frequencies and he mentioned that he did this research on that topic before beginning his experiments on the mmWave channel measurements few years ago:

It is obvious that using these frequencies (i.e. mmWaves) is far from ionization that causes health issues for humans if they are used in the right way and according to federal regulations.

Best Regards.

This question iv very interesting. To answer this question clearly one has to define exactly what is the memory effect in the power amplifier. There is a principle concerning the measurement of the quantities. The quantities are measured as they are defined.

Memory means to preserve information when the time elapses. So, it is a direct time domain effect. It is so that one can preserve a analog sample for specific time in a capacitor. So, if the devices are containing energy storage effect they will show some memory effect. The memory effect in an amplifier can be tested by applying a pulse on the amplifier and then observe how long this pulse can last after the input pulse is removed.

If there is no memory effect the two pulses will follow each other in the time variations. This is straight forward from the transfer characteristics of the strictly linear amplifier Vo= AVi with A is the gain, Vo is the output voltage and Vi is the input voltage. So Vo is a replica of the output and no memory effect at all.

So, we have to define the memory effect on time domain and then determine it in the frequency domain.

Best wishes

there is a tutorial at ANSYS. My recommendation - first use eigenmode solver on one cell with periodic boundaries to see approximate dispersion. Floquet port works for wide structues and refracting arrays.

then use standard driven modal. Just my recommendation - add air/material dummies in the structure, near gaps, boundaries, and seed them manually. HFSS can "skip" meshing such things like interdigital capacitors, and give out wrong results.

1) 3.5/3.7GHz : Band n77/n78

2) 4.5GHz : Band n79

3) Upto 6GHz : BW>500MHz (WRC15 band)

4) 10GHz, 17-18GHz, 24-25GHz, 27-30GHz, 32GHz, 36GHz etc (WRC19 band)

5) 26/28GHz : Band n257/258

6) 38GHz, 40.5-43.5GHz, 60GHz etc freq. bands

Dear brother Lway,

your question is about the possible use of UWB antenna for 5G. As for the possible applications of the UWB communication system as it is standardized by ITU, it is a very short range communication system. Mobile communication systems are wide area communication systems. So, i agree with you the UWB communication systems are thought to complement mobile communication network like WIFI and blue tooth to save cost and congestion of the wide area networks. For more details about the possible applications of the UWB systems please refer to the link:https://core.ac.uk/download/pdf/29820629.pdf

Best wishes

Thank you Prof.Amina Bouraoui

You could focus on how close to optimal the routing algorithm is. But getting closer to optimum becomes unimportant after the algorithm's performance becomes good. More important are questions about how much bandwidth is used by the signaling and management overhead of the algorithm, and how robust the algorithm is to changes in the topology of the network.

For example,

(a) How often do the components have to communicate in order to maintain the current network structure and how much information do they need to communicate?

(b) When network components leave the network or new components enter or existing components change their connectivity relationships, how much signaling and management bandwidth is required to keep the network operating efficiently and without disruption?

These questions should probably be posed so that the measures of quality include (1) ratio of overhead bandwidth to useful,, traffic-carrying bandwidth and (2) loss of bandwidth efficiency as the network topology changes and the network is reconfiguring itself.

Also, is the algorithm brittle, so that usual changes might require large amounts of signaling and management to restore near-optimality for trans-network communications, or is it robust to changes so that even as the network morphs, overhead remains small and nearly constant? Are there scenarios where catastrophic reductions in traffic-bearing bandwidth will occur? If so, how should you make the network more robust?

I think that as you consider issues like these in addition to near-optimality issues, other questions will occur to you and you will be on your way to designing a well-engineered real-world system.

I am still trying to understand if the time alignment to PCell's time frame structure is really necessary. It seems there could be non-time aligned transmissions by the SCell as long as it transmits the necessary signals (RS, PSS, SSS, BCH, etc.).

Does anyone know if there is some kind of limitation to non-aligned transmissions?

Hello,

For 3G and 4G communication, frequency is arranged or taken according to antenna used and feasibility of manufacturing antenna. Wi-Fi frequency is fixed according to IEEE standards which is 2.4 GHz, but to enhance bandwidth to use more and more channels, frequency is increased in limited gain. Now selecting frequency, is depending on other parameters of communication systems.

refer the papers.

Thanks,

Kindly see this reference (Paper title: Social Media, Collaboration, and Scientific Organizations).

I suggest that you look at the Bradford Hill criteria : https://en.wikipedia.org/wiki/Bradford_Hill_criteria

These give you some idea of the data we would need to show significant danger from mobile phone radiation. 

As we stand on the brink of a mass extinction, we have more to worry about than hypothetical dangers. Let's try and work on the real threats to the planet. 

I think maybe we are just talking about different protocol layers? It's a bit like asking why IEEE 802.3, the Ethernet standard, doesn't address security. Security is built on top of Ethernet. At least, that's the typical way of implementing security.

The other point is that a telecom does need to implement security measures, but this is primarily to protect itself. For example, their system management messaging, routing tables and routing protocols, have to be secure, to prevent a hacker from disrupting the system. But it doesn't do much good for the telecom to secure user traffic, if ultimately, at the edges, the traffic has to be sent in the clear. If a user of the telecom wants security, that user must install a solution that protects traffic end to end, from inside his PC or smartphone, all the way to inside the PC or smartphone at the other end. Or in the case of an enterprise network, security could be implemented until the link is inside that enterprise's "secure enclave," perhaps not all the way to the end system. So for example, the enterprise may deploy secure tunnels, through a telecom network, where the end points of those secure tunnels are inside secure enclaves.

Otherwise, anyone along that path would be able to monitor the communications. And there is no reason for a user to trust the telecom itself, ultimately, if that user needs security.

Security can and is implemented at any protocol layer. From the standpoint of a user, though, any security measure that is not end to end would be of questionable value. That's why people use Transport Layer Security so often, when dealing with communications across telecom or other network services. It's security built over the telecom link, carried transparently by the telecom or by the digital network.

Thus it can solve the Uplink capacity shortage of  mMIMO system.

Rayleigh fading only gives you diversity order of one, while the Nakagami-m fading model will provide you with a diversity order of m. Having said that, both Rayleigh and Nakagami-m model will not describe the line-of-sight (LOS) transmission environments well. Some authors proposed to use the Nakagami-m model to approximate the Rician fading, and such an approximation is not recommended since both models donnot even give you the same diversity order, and Nakagami-m cannot be used to describe the LOS transmission, which has been empirically verified (Read the paper by Molish). Another reason why the Nakagami-m model is popular is because its mathematical form is more analytically tractable.

Dear Dr/ Profir

I will send some of reference about mentioned subjects,

You recommend Books or Papers.

best regards

@Javier and @Sudarshan thank you very-much for your valuable advice. 

This will help me in my research. 

It;s a celebrated method in crowd-sourcing research community. Mobile empowers the network with enormous number of potential nodes around the globe which can be used to collect data, verify it and update it.

Corwdsourced disaster reporting and alerts is a naive use case.

Hi

Find the following URL documents may help you:

Regards...

Outage probability is the probability that a system does not function as per the expectations, such as the probability when the instantaneous SNR falls below a threshold SNR. But if the SNR considered is received SNR, then that received SNR which depends on the wireless channel could be considered random. So, we need to average out the received SNRs for various channel realizations. Hope this helps. 

The following document may help you:

https://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.1238-7-201202-S!!PDF-E.pdf

Hi Alison, 

for teaching biomechanics I often use an app from the a Technical University of Aachen/Germany named 'phyphox'. They also implemented some nice experiments for students.  see details here ----> http://phyphox.org

Regards from Cologne / GER

Bjoern

I'am looking for a CDR structure for a Nokia's MSS system working on software M15 version too. Is there so easy to get the name of those storage to go there and then download it? Please I would like to know those? Regards 

As far as I know, this has not been decided yet in 3GPP. But almost all the companies involved in 3GPP have proposed different forms of OFDM. So it is quite likely that 5G will use OFDM with additional filtering or tweak to better support certain types of traffic.

Please note that the modulation choice (such as OFDM) has little to do with increasing the spectral/energy efficiency in 5G. Higher data rates will be achieved by a combination of MIMO transmission and using more bandwidth.

hi

It's a difficult question, where are you Implement the algorithms. for example if you implement the algorithms in the C/C++ you must use time.h and sample header files to compute latency time.

Good overview can be found on the following link: http://www.wiley.com/legacy/wileychi/zarrinkoub/supp/PowerPoint_slides/UnderstandingLTEwithMATLAB.pdf

Dear Muhammed, 

The specifications of the mobile handsets in the given link may be of interest to you.

In addition mobile phones are built to satisfy the ITU standards.

The link:http://www.devicespecifications.com/en

wish you success

Khalid's answer is very interesting, implying that the "smallest unit assignable" would be, ultimately, something like 9.6 kb/s, for a voice cellphone call over 5G, to one MVNO sharing that 5G infrastructure.

In the US, cellular companies have not operated this way, ever. Originally, with analog service, yes, they were sharing each other's infrastructure, but when your phone was out of reach of its "native" service, you would be charged so-called "roaming charges."

Then, with digital 2G and more so 3G service, that roaming practice essentially ended. In my experience, the first 2G phones could roam over someone else's analog, but soon that ended. And in the US, by 2008, all analog cellular stopped.

So, I truly wonder whether the concept of virtual operators, sharing the same infrastructure, will ever happen with 5G in the US.

You might want to look through some of these presentations.

LTE carrier aggregation, including possibly aggregating LTE carriers in the unlicensed spectrum, treats the aggregated LTE carriers as one wide LTE channel. Whereas if LTE offloads traffic to WiFi, that is a separate link, using the WiFi protocol for access, IP routing, and so on. And, importantly perhaps, the cellular carrier will not make revenue off the WiFi session, as the cellular carrier might make if the aggregtaed link were another LTE channel, or even LTE-U (LTE over the unlicensed spectrum).

Thank you, Michael :-)

And sorry for my late answer

Die gsma hab ich in meinen Recherchen bisher einfach übersehen. :-(

A circular patch antenna can be treated as a circular cavity and it supports modes which are perpendicular to the patch, as with a rectangular microstrip antenna. The first mode (TM11) produces a broadside radiation pattern. At higher frequencies, the second mode (TM21) get excited and this mode produce conical radiation pattern with lower gain.

P.Xie et al. developed a new UWSN simulation package called Aqua-Sim. This simulation tool follows the object-oriented design style of NS2, supports three

dimensional modeling and it can simulate acoustic signal attenuation, propagation delays and packet collisions. AquaSim integrates very easily the existing codes of NS2 and has an adequate number of MAC and routing protocols specially

designed for UWSN. Finally, because of the lack of a NS2 NAM animator to visualize 3D UWSNs, uses an additional tool, the Aqua-3D animator. on the other side UWSim is also a simulator that has been used for underwater sensor network modeling. This simulator designed and implemented for testing scenarios specific to UWSN environments, such as low bandwidth, low frequency, high

transmission power, and limited memory.The software development follows C# object-oriented programming and it is based on a novel routing protocol proposed by the

developers. Currently, UWSim has support for a limited number of functionalities, it is custom-designed for a specific algorithm and it calls for further extensions to support a wide range of UWSN simulation scenarios.

i hope it's useful.

best regards

Dear Moiz,

sorry, i am not an expert in this field,with my little knowledge i can  say the schemes are valid for that particular generation and of course  there will be backward compatibility with the new generation with a truncation error in the data.

with regards

vasanth 

I am unable to attach the paper. Please see:

[1]    W. Wiesbeck, L. Sit, “Radar 2020: The Future of Radar Systems,” in Radar 2014 Conference Proceedings, Lille, France, 15. Oct. 2014

Thanks Sir for ur reply. If we want to simulate the system using monte carlo simulation the what is the procedure? Do we require mean and variance of these channels to implement this?

Hi Marwan,

you can find several traces as datasets in my publications list. I have several papers on a mixed indoor-outdoor environment with associated datasets. Feel free to contact me for more information. As an example, see publications attached to this post. Critical can be the fact that we never recorded the elevation/altitude since we are doing 2D localization. However, you can simply add the altitude as 2 m yourself to the traces since the UAV, we used to sense and record data, was keeping the altitude constant at  2m. Good luck.

Thank you for your interesting answer.

In my opinion it is not easy to understand this phenomenon.

We need to have a great experience to understand it

 

We can classify the power efficient routing protocols into four categories based

on their path selection scheme. The first set of protocols use the energy cost for transmission as the cost metric and aim to save energy consumption per packet. However, such protocols do not take the nodes’ energy capacity into account. Thus, the energy consumption is not fair among nodes in the network. Minimum Total Transmission Power Routing (MTPR) is an example protocol for this category. The second set of protocols use the remaining energy capacity as the cost metric, which means that the fairness of energy consumption becomes the main focus. But, these protocols can not guarantee the energy consumption is minimized. The third set of protocols are similar to the second set, but use estimated node lifetime

instead of node energy capacity as the route selection criteria. Therefore, these protocols still aim to fairly distribute energy consumption. In order to both conserve energy consumption and achieve consumption fairness, Conditional Max-Min Bat-

tery Capacity Routing (CMMBCR) has been proposed to combine these two metrics. CMMBCR is an example of the fourth category of protocols, which use combined metrics to represent energy cost.

Kapiolani,

I do not think that they consciously compare the two levels of activism and choose one. I think that it is a question of levels of motivation.  Sharing a link or temporarily changing a profile picture is easy to do and may be perceived as "doing a little to help."  

The choice to attend a rally, etc., requires a higher level of motivation...and this motivation is often produced by the persuasive characteristics of the original message, or the perceived threat.

Hum.  Maybe the framework of instrumental versus integrative motivation can be applied here.  Is it possible that low risk online actions can best be seen as mostly externally (instrumentally) motivated, whereas higher-risk engagement is he result of internal integrative motivation?

The problem with OFDM, when rapid motion is involved, is Doppler shift, which causes inter-carrier interference. The link below looks into ways of compensating for inter-carrier interference, which would then permit the use of higher modulation levels with less BER degradation.

Another obvious and well known technique, and cheap, which may make it "efficient," is to simply limit the OFDM mode to fewer subcarriers. This improves performance for mobility, but it reduces the tolerance to multipath distortion. All else equal (specifically, if you maintain the same spectral efficiency), the fewer the subcarriers, the shorter the symbol duration, the shorter the guard interval, the less tolerant the system becomes to reflections in multipath propagation.

Just to give an example, in an 8 MHz DVB-T2 channel, if 32K mode is used, the spacing between subcarriers is 250 Hz. If the carrier frequency is 600 MHz, typical for TV UHF, then the Doppler shift at 100 km/h will be up to 111.2 Hz. That's a huge percentage of the 250 Hz subcarrier spacing. If instead you use 2K mode, subcarrier spacing is a much larger 4000 Hz, which makes the Doppler shift of 111.2 Hz rather inconsequential.

Cooperative communication is a good solution to mitigate interference between users and btween cells in the form of distributed MIMO. Try search LTE-CoMP

The most comprehensive coverage model I know is the Longley-Rice model:

Although I have to say that the modified Hata model often gives me very good results, and it is a whole lot simpler!

The key technologies in 5G H-CRAN networks include cloud based cognitive processing advanced spatial signal processing, cooperative radio resource management, network function virtualization,  self-organizing traffic-driven and user-centric network.To avoid the inter-tier interference, the cognitive processing technique is utilized to make RRHs and ACEs work cooperatively in the overlaid scenario when the overall system load is not high. The radio resource cloudization  decreases the inter-tier interference and improve the flexibility of radio resource’s reuse and thereby  improves the SE performance when the overall system load is high. Hence the conventional handover management is not of a concern at least at this current stage of technology development.

This toolbox might serve as a starting point.

Hello,

I think it is a good idea because you can control the dynamic range of adaptive filter by using a fixed filter. Fixed filter can be designed to overcome the intermodulation effects as the mean of the total stochastic process.