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These legacy private networks were suitable for connecting laptops to the Internet and for other limited industrial IoT (IIoT) use cases. However, the coverage and security limitations of these networks, their incompatibility with public cellular networks, as well as their high costs of ongoing management have made it difficult for organizations to use these networks for many IIoT applications. How to reconcile the two? Any related papers? Thank you in advance! To see more: https://www.sierrawireless.com/iot-blog/what-are-private-lte-networks/
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yes, but you need a private frequency spectrum and ready to bear huge initial cost .Current wifi networks are not as much costly as your private 5G.
CHECK YOUR COUNTRY if it allows you private frequency spectrum.
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5G technology has a theoretical peak speed of 20 Gbps, while the peak speed of 4G is only 1 Gbps. 5G also promises lower latency, which can improve the performance of business applications as well as other digital experiences (such as online gaming, videoconferencing, and self-driving cars).
While earlier generations of cellular technology (such as 4G LTE) focused on ensuring connectivity, 5G takes connectivity to the next level by delivering connected experiences from the cloud to clients. 5G networks are virtualized and software-driven, and they exploit cloud technologies.
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in 5G radio we need every 15 km EnodeB which increases SNR which affects directly the UE device if there's no filter to convert this signal into Redicuation use .
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In looking at charging records, for each MMS message, there appears to be a matching data session open, however, in some cases, I see the data session stay open for an hour after the message was sent and often see multiple MMS messages in one data session. Is there a data channel like the QCI 1 and 5 when a voice call is made?
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Good information, Eric. The trace will be a good answer in a live system. I am trying to determine if the system's design (STANDARDS) will first establish a data session to transmit the MMS. In the charging records provided after the delivery, will the charging records show one CDR for the data session and a second for the MMS?
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Aamir Habib Would you know the average gain in each of the 2 layers when TM mode 3 - open loop spatial multiplexing - is used?
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Hi there,
I am studying the impact of numerology and mini-slots on several proposed algorithms to achieve fairness between 5G NR-U and Wi-Fi networks over unlicensed spectrum bands. However, the coexistence of NR-U and IEEE technology (802.11ad) Wireless Gigabit (WiGig) at 60 GHz bands has been implemented within ns-3 in a 3GPP indoor scenario but there is NO working example for for this coexistence (i.e., I could not compile the code) because the authors have shared the codes, but the users cannot compile it. Can anyone recommend any such codes that I can compile for such scenarios?.
Regards,
Moawiah
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I'm trying to make a comparison between a numerical setup and LTE simulation results but I need to know knowing the capacity of the BSs in my experiment so I can make a meaningful comparison. From my simulation using FTP traffic, I have avg user&cell throughputs, spectral efficiency, and resource block utilization, but from what I have found in the literature, I can't quite estimate the capacity of the BS. Help is greatly appreciated in advance.
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The maximum theoretical LTE throughput can be calculated by referring to the standard tables in 3GPP TS 36.213 based on the following steps:
1. Determine the number of resource blocks used for a given bandwidth.
2. Select the Transport Block Size (TBS) based on the MCS value using table "Table 7.1.7.1-1: Modulation and TBS index table for PDSCH" in TS 36.213.
3. Based on the TBS, determine how many bits can be transmitted in a subframe using "Table 7.1.7.2.1-1: Transport block size table" in TS 36.213.
4. As there are 1000 subframes in 1 s duration, multiply it by 1000 to get bps. Finally, divide it by 1 M to get Mbps.
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hi
i want to know more about 5G and LTE channel parameters like (path loss, carrier frequence, max transmission power) etc.
thanks
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Ananya Hegde thank you so much, ill check it out
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Hello dear
i have been reading a paper
'A Matching Game Approach for Resource Allocation in Wireless Network Virtualization'
that suggest a scenario which there is BS form infrastructure provider containing 10 subchannel with 180 KHz width, and the BS serve 3 virtual wireless network that contain 5 user and FDMA technology used. So, i wonder about how do subchannel distributed in virtual wireless network?
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Dear Tariq, you mentioned 10 subchannels, shouldn't the number of subchannels be a power of 2? Like 8, 16, 32,.....128,.....etc? I might be wrong so please check it. Regarding your question, do you ask about the subchannels distribution nature? as in terms of Rayleigh or Rician, or you meant allocation?
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Hello experts,
I hope you're good.
I am trying to generate non binary (optimized) lfrs sequence on the fly with c.
But I am missing something, I don't get what ...
attached is the code ....
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Are the simulation results giving a good impact on real-time problem-solving?
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It depends a lot on what aspects of the networks that you want to simulate. The big simulators that the industry are using have very high complexity.
A new open-source initiative that might be of interest to you is Sionna: https://nvlabs.github.io/sionna/
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Dear researchers;
I am looking for a simulator that gives me the ability to generate a heterogeneous wireless network environment composed of radio access technologies, such as 3G, 4G, 5G, Wifi, etc.
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You can use NS3 or Atoll
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dear sirs
what is the main difference between the 4G-LTE and the 5G -LTE , and how we can implement the LTE concept in the 5G new radio?
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4G is the branding name for LTE, while 5G is the branding name for NR. Hence, I would say that there is no such thing as implementing 4G/LTE in 5G/NR.
However, the 5G standard builds heavily on 4G standard, to the extent that it can sometimes be deployed as a software upgrade of a 4G base station and where a 4G core network can be used. But it is not backward compatible in the sense that a 4G device cannot connect to a 5G base station.
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As it is known that the electron temperature Te is a vital parameter to describe plasmas properties and it is higher than the neutral temperature Tg in cold plasma so that the LTE is no longer valid. So, the diagnosis of Te by using the LTE approximation method is not credible.
Kindly provide help on this matter.
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Sushil Kumar K.C. , for new sources of non-thermal plasma, you can look on these publications:
A new type of non-thermal atmospheric pressure plasma source // J. Phys.: Conf. Ser. 1393 (2019) 012062 doi:10.1088/1742-6596/1393/1/012062
A new type of non-thermal atmospheric pressure plasma source based on a waveguide bridge // 2021 J. Phys.: Conf. Ser. 2064 012131
"Microwave complex for obtaining low-temperature plasma at atmospheric pressure" // Journal of Physics: Conf. Series 1393 (2019) 012042, doi:10.1088/1742-6596/1393/1/012042.
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Dear All.
I am working in LAA WiFi coexistence scenario. For my work, I need to calculate the Latency/Delay in a different way.
From my understanding, the way current solution is calculating the delay is that it is monitoring the time between the packet was first transmitted and last seen from the receiver's perspective. It is done in the FlowMonitor class where you calculate all the delay into delaysum and calculate the average delay.
Now, what I want to do is that, for every received packets, I want to set a timer when the packet is being generated and add with the individual delay values and calculate the avg delay. Now, as I am talking about the LAA-WiFi coexistence, I cannot make a solution that only works for Wi-Fi. So I have to solve this problem from the base, I mean, the Packet class.
Did anyone work in this problem before? Need some expert suggestions. And Thank you in advance for your kind assistance.
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I am in search of any advanced simulator for testing the Coexistence of LTE and WiFi scenario in different cases.
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I recommend NS3.
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I am trying to find resources where I can study the comparison of the various features of the Random access channel in LTE using simulated and real-world measurement data. It would be great if you can help me to find any resource on that.
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Hi,
you can try OpenAir Interface https://openairinterface.org/ and the associated code for 4G/5G deployment and test:
regards,
Vincent
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Searching a Research tool for doing the research of LTE and Wi-Fi Coexistence with fast speed and with good accuracy.
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In general ' Network signal guru is better.But ,it is better to specify your objective more clearly as you want to describe with specific parameters.
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I have gone through some of the simulators like Vienna simulator, LTE Pro, NS3. But I am not finding comfortable to proceed with my work. Do you suggest me the best simulator?
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try matlab 2021 version . got good toolbox for 5G
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I am trying to understand what is included in Charging Data Records and when they are produced. There much a principles document and a Stage 2 and 3 documents in 3GPP but I'm not finding it.
Also, any good text on Charging in LTE would be appreciated. Thank you.
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Apart from experiments available for WiFi, IoT, LTE etc., we also want our students to work on experiments on 5G. Does someone have a set of pre-built NetSim experiments which we can quickly adopt for our course? If not, any suggestions on what kind of experiments can be done would be valuable? Thank you.
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NetSim support a range of technologies, including the capability to interface Matlab and C++ programs. So if you want to integrate 5G in a Netsim experiment, you will need to deploy the 5G experiment in Matlab then interface it with NetSim for full deployment. I hope this answers your question.
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I see in an LTE data session that the UE is changing RAN. For the one-hour session, the UE shows 12 cell towers used. There is a second session that only shows 2 cell towers used over the same period of time.
Is data session #2 idle therefore does not do an update? And is the first session very active while driving?
What is triggering the update?
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I'm not sure either, but the EMM TAU Update accept message optionally includes a list of EPS Bearers, and if the bearer for any service is not included then presumably it does not accept a TAU - so would not be included.
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How does increasing mimo order in enb cell helps with capacity increase in the LTE cell. means when we go from 2x2 mimo to 4x4 to 8x8?
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Dear Vikas Nain ,
I wonder how the UE have two antennas and your system is 8x8 MIMO.
8x8 Mino means that NtxNr =8x8 , this means that Nt=Nr=8.
Any how for a single user 8x8 MIMO system
The maximum capacity of the system = 8 times the capacity of the SISO system.
This maximum capacity can be achieved for the presence of at least 8 independent paths between the transmit and receive antenna system.
The same concept applies for the higher number of equal transmit and receive antennas. There are many papers which calculates the maximum channel capacity for conventional MIMO and for massive MIMO.
Best wishes
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Do cellular phones which support LTE have Diversity/MIMO antennas in the 700 MHz bands in addition to the higher bands?
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I would like to pay your attention to the pdf found in the link:https://www-file.huawei.com/-/media/corporate/pdf/mbb/2020/4x4-mimo.pdf?la=en
They speak about user equipment having up to 4 antennas. We developed MIMO antennas for the mobile phone:
Best wishes
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I want to estimate TOA and CFO of LTE signal. TOA is estimated for oversampled signal. after TOA estimation, the CFO is estimated. Please let me know, why the estimated CFO is wrong?
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What is the approach used to achieve estimation?
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Hi
Hope you are well.
Can you please share your code for D2D implementation in Matlab.
I want to implement D2D in Matlab based Vienna simulator and struggling to deploy D2D.
Thanks
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Matlab does support LTE-Advanced wireless communications systems.
It has dedicated toolbox for the same as LTE System, for end-trend simulation, signal generation, V2X communication, etc
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Hello, I am a beginner in ns3.
I would like to add an energy module to the UE node to check the battery changes of the UEs.
By the way, it seems that ns3 only supports wifi energy module.
Does ns3 have no energy module for LTE?
If yes, is there a way to use the energy module in LTE?
Best Regards,
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Data such as L7 protocols used by the UE s and the resources used (forward bytes and backward bytes)
Data should preferably look like this:
Timestamp(in milliseconds) | Type of application| Protocol used | forward and backward resource blocks used or no of bytes for the whole transmission.
I tried kaggle and other open resources available but I was not successful in getting data for this use case.
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It is better to consult BSS engineer to get how much data per channel is transmitted by BTS to a particular connected user.
Alternatively! How much data are being received by your mobile ( in 2g/3g/4g) in concerned network can be seen by Net monitor app more easily.
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I'm reviewing charging data records (CDRs) from a mobile carrier for one user's cell phone and I notice that for many of the voice calls, there is an associated data record that starts about 1 second before the voice call and is torn down at the end of the voice call.
Is this a feature of an LTE or 4G voice call? What is the purpose of this data channel. It appears to use approximately 40 K of data in the uplink and downlink directions for each call.
Thank you.
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I'm not sure whether "voice over LTE" service, specifically, requires a data channel, but "voice over IP" does. If your voice calls, over a 4G/LTE network, sometimes (but not always) have an associated data channel, then my bet is, those are VoIP telephone calls, where the cell phone is using an IP network, to make the phone call.
When voice calls are made, from an IP network to the standard public switched telephone network (PSTN), or vice versa, there has to be a server involved, to map the PSTN telephone number with the IP address being used by the VoIP side of the connection. This is always needed, whether the call is going out on, or coming into, the IP network.
And it makes sense, right? The standard 10-digit telephone number, or other schemes used in other parts than North America, are not native to IP networks. Something has to do the translation, and something has to provide the steady stream of packets, required to keep that phone connection alive.
If you want to know the details, this RFC 3372 describes the Session Initiation Protocol (SIP), used in the IP end of that phone connection.
SIP-T is not a new protocol - it is a set of mechanisms for interfacing traditional telephone signaling with SIP. The purpose of SIP-T is to provide protocol translation and feature transparency across points of PSTN-SIP interconnection. It intended for use where a VoIP network (a SIP network, for the purposes of this document) interfaces with the PSTN. Using SIP-T, there are three basic models for how calls interact with gateways. Calls that originate in the PSTN can traverse a gateway to terminate at a SIP endpoint, such as an IP phone. Conversely, an IP phone can make a call that traverses a gateway to terminate in the PSTN. Finally, an IP network using SIP may serve as a transit network between gateways - a call may originate and terminate in the PSTN, but cross a SIP-based network somewhere in the middle.
There is a more basic RFC to cover SIP, in general, not necessarily related to telephone calls made over IP networks. RFC 3261:
There are many applications of the Internet that require the creation and management of a session, where a session is considered an exchange of data between an association of participants. The implementation of these applications is complicated by the practices of participants: users may move between endpoints, they may be addressable by multiple names, and they may communicate in several different media - sometimes simultaneously. Numerous protocols have been authored that carry various forms of real-time multimedia session data such as voice, video, or text messages. The Session Initiation Protocol (SIP) works in concert with these protocols by enabling Internet endpoints (called user agents) to discover one another and to agree on a characterization of a session they would like to share. For locating prospective session participants, and for other functions, SIP enables the creation of an infrastructure of network hosts (called proxy servers) to which user agents can send registrations, invitations to sessions, and other requests. SIP is an agile, general-purpose tool for creating, modifying, and terminating sessions that works independently of underlying transport protocols and without dependency on the type of session that is being established.
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I would like to do some experiments while applying packet loss. However, I want to follow some well-referenced packet loss settings, which consider to some extent different networks' conditions. For instance, 1% packet loss in the mobile network in driving use case (where end-user is videoconferencing or playing a video ..etc), 3% in a congested network while the is playing an online game, ..etc.
We are interested in packet losses caused at layer 3-4 (i.e., to implement erasure channels) but we are looking for the typical packet loss percentage for a variety of use cases.
My question: Is there any paper or article with justification for typical packet settings align with use cases?
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I am going to make a security protocol (for authentication) and I found AVISPA is good choice)..but also I am going to see the overload of my protocol on LTE network when I use my security protocol. with MATLAB how can I check my protocol overload in LTE network..
Many thanks
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Hello there!
I'm currently doing my BSc project which requires codes on an LTE link whether it is a simulation or a code of real implementation
But I really can't find any good resources on this not a book or paper or anything else
I would really appreciate your help because I'm in an urgent need of this
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Dear Mobin,
welcome,
You can find the LTE system implementation using Matlab by following the paper in the link:
If you have any question on the code you can ask the first author.
Best wishes
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Outdoor obstacles, such as buildings, buses, and trees, interfere with radio signal propagation by contributing fading and shadowing and path loss effects. I want to evaluate the impact of these obstacles in the LTE communication Channel. So I need help to model the effects of the obstacle using Matlab. Thank you
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The path-loss can be modeled using Friis equation Loss=(4*pi*f*d/c)^n
n: is the path-loss exponent it depends on the type of material the wave propagate through for example, in free space its numeric value is 2. you can find the path-loss exponent for some materials for some cases in this link:
Some channel models are already used for LTE cellular communication considering these factors like Hata's model, Hata's extended model and Okumura's model and they have formulas for urban, suburban and rural environments. You can search them and choose the what is convenient for you. Hope it helps
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I need reference papers (recent) on the various LTE traffic types and their usage distribution. My aim is to obtain a reference like this: VoIP =xy%, FTP =j%, Video =z%...
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You can check
1) Chapter 19 of the book [F. Khan, "LTE for 4G Mobile Broadband: Air interface technologies and performance". Cambridge University Press, New York, USA, 2009.]
2) Appendix B of 3GPP. LTE physical layer framework for performance verification. TSG RAN1 48, R1-070674. [Online] Available: http://www.3gpp.org/DynaReport/TDocExMtg--R1-48--26033.htm
3) Table III in the paper “System-Level Performance Evaluation for 5G mmWave Cellular Network,” in GLOBECOM 2017 - 2017 IEEE Global Communications Conference, Dec. 2017, pp. 1–7, doi: 10.1109/GLOCOM.2017.8254055.
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In the Random Access procedure which is performed by MAC layer it selects preambles from set A and B with equal probablility for each set.As there is only 64 number of preambles why it has to be divided into two groups.is there any significance for each group?
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Group A: When the UL data quantity is relatively small and UE is in Poor Coverage.
GroupB: When the UL data quantity is relatively large and UE is in good coverage.
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The data should contain QCI and QoS related parameters and I am using it for designing Network slices, where can I find data like this?
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I don't know whether you are looking for this sort of data or not. You can still check this out
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with a well known fact that the success of the 5G technology vastly depends on how well it fared in indoor venues, with analysts claiming that more than 80% of mobile use and tearric originates indoors, what are the available specialized solutions that can make the technology succeed indoors, while keeping both its QoS possible health hazards in check.
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hi Orogun 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.
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In this case, CFO and TOA are not independent variable. Transmitter send several packet. In the receiver side, first the TOA of each packet is estimated then the CFO of received signal is estimated. So, the error in TOA estimation result in error in CFO estimation.
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Thank you Igor Dotlic
Please introduce me a paper.
In the LTE scenario, the receiver first should estimate the TOA of received signal then estimate the CFO based on the following paper:
F. Wang and Y. Zhu, “An efficient CFO estimation algorithm for the
downlink of 3GPP-LTE“ .
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Hi all,
I have two questions about random access procedures of NB-IoT
In NB-IoT, Nprach-Periodicity is the amount of time between two consecutive random access transmission attempts.
Random Access procedures include preamble (Msg1) and its repetitions, random access response RAR (Msg2), Msg3, and contention resolution (Msg4). Following that, actual data transmission starts.
Question is:
1- Do all of these steps happen within one Nprach_Periodicity? (such that UE can start another transmission immediately in the next periodicity)
3GPP standards were not clear enough about these points and they didn't show exactly the time elapsed in Msg3, Msg4, and actual data transmission.
2- When a collision happens in Msg1 transmission (2 UE choose the same subcarrier), collided UEs have to choose a backoff time in the range of [0 Backoff]. There are several Backoff values and eNB can inform the UE which Backoff value it will choose. How does the eNB identify the suitable Backoff value in each collision case? is it affected by the number of failed attempts?
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Though from my understanding of question 1: Msg3, Msg4, and data transmission should happen all before the next periodicity.
-> I don't think so: the periodicity only indicates when the UE is allowed to transmit NPRACH. It is independent of the other scheduling parameters for Msg3 and Msg4.
In fact, mac-Contention-ResolutionTimer which is the window for receiving Msg4 transmission can be between pp1 to pp64 in which pp indicates NPDCCH period. But what is the actual period of pp in milliseconds?
-> I never met pp in the standard, do you have a reference please?
Best regards,
Vincent
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Is there differents between 5G and orhers ICT infrastrure in terms of smart grid applications? For example, is there any different between 5G and LTE?
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Mahdi, please note that 5G is widely believed to be smarter, faster, and more efficient than 4G. It promises mobile data speeds that far outstrip the fastest home broadband network currently available to consumers. With speeds of up to 100 gigabits per second, 5G is set to be as much as 100 times faster than 4G. Therefore, it is able to handle more data exchange capability and may help the controllers of renewable resources, etc to respond faster and thus, improve the dynamic performance of smart grids. However, what's more important, I think, is the topology and configuration of the communication system. It is expected that future communications systems configurations are inclined to be more distributed through distributed micro-antenna.
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In LTE, is is possible to perform different modulation schemes on different resource elements in a resource block of a user?
It would be appreciated if you supply me with helpful articles or books.
thanks in advance
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Dear Faten,
Yes every resource block can have different modulation order since even every subcarrier can have its own modulation order.
Best wishes
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Hello everyone,
I'm trying to get LTE RSRP, RSSI, RSRQ, SINR, equations and values using Matlab code, however the values don't make sense for me since RSRQ value is around 75 while the standard range is -19.5dB(bad) to -3dB (good).
Please your kind support and guidance.
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The power amplifier is a 3 stage device and the output fluctuation is probably due to the final stage only as we have tested them individually. But how to solve the problem is the basic question which can be answered if we know what causes it. I doubt that there is a grounding problem, and tried some things, but was unsuccessful.
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Sarika Shrivastava can you please elaborate which filters are you talking about exactly ? I suppose filters on biasing voltage for the transistor ?
I am also having same issue but its not in complete frequency band.
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I am in need of LTE and Wi-Fi Coexistence Algorithm. If any one is having it and or can give any reference then please share it with me.
Thanks.
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Every modern smartphone can do this, simply turn on your hotspot and see the coexistence, finding such an algorithm should not be a research question today. Also check:
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For higher accuracy, should not the LTE Path Loss Models take into account every single resource block frequency? The path loss will be different for each resource block (RB). For example, if I am operating at 1900 MHz with a 20 MHz channel, there would be 100 RBs (each is a different sub-carrier). Surely the path loss cannot be the same over all the subcarriers.
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Dear Abullah,
Adding to the colleague Emil above, this is what is really considered in the channel estimation in the OFDM or the multicarrier system. This is also the point of strength of the the OFDM since the wide band channel is divided into many narrow band channels. Frequency equalizers are used to correct for the channel impairment.
Practically the channel is estimated by the use of frequency pilots whose number is sufficient to estimate the whole channel complex transmission coefficient.
Also interpolation in the time domain can be be accomplished by the proper pilot distribution.
For radio sizing of the system and radio design one utilize the link budget in including the path loss an addition to the fading margins. For the variations among the the frequency band one uses equalizers.
Best wishes
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For higher accuracy, should not the LTE Path Loss Models take into account every single resource block frequency? The path loss will be different for each resource block (RB). For example, if I am operating at 1900 MHz with a 20 MHz channel, there would be 100 RBs (each is a different sub-carrier). Surely the path loss cannot be the same over all the subcarriers.
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I saw that you posted the questions twice, so I'm going to add my reply twice:
You are right and this is taken into account in the 3GPP (LTE) channel models. There is usually a pathloss model that provide the average pathloss over time and frequency. On top of that, there is frequency selective fading and time-domain small-scale fading, which create smaller variations between resource blocks.
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There are multiple modulation options available for LTE resource block allocation (BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM) depending on channel conditions. This modulation scheme is applied to all the resource blocks allocated to the user; in other words, each subcarrier in each of the allocated resource blocks are modulated using one of the above-mentioned schemes.
This means, if 16-QAM was chosen, then subcarrier 1 in resource block 1 will be modulated with 16-QAM, subcarrier 2 of resource block 1 also with 16-QAM, and so on for all the subcarriers within that resource block and all the other resource blocks assigned to the user.
Furthermore, two users can be allocated the same resource block over two different time slots (on the frequency-time grid) with distinct modulation schemes for each user.
This may seem to be a rather simple question, but my adviser does not seem convinced that the above understanding is completely valid.
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You are quiet welcome. Yes, as far as I can tell, for each resource block the same modulation technique should be used.
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There are multiple modulation options available for LTE resource block allocation (BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM) depending on channel conditions. This modulation scheme is applied to all the resource blocks allocated to the user; in other words, each subcarrier in each of the allocated resource blocks are modulated using one of the above-mentioned schemes.
This means, if 16-QAM was chosen, then subcarrier 1 in resource block 1 will be modulated with 16-QAM, subcarrier 2 of resource block 1 also with 16-QAM, and so on for all the subcarriers within that resource block and all the other resource blocks assigned to the user.
Furthermore, two users can be allocated the same resource block over two different time slots (on the frequency-time grid) with distinct modulation schemes for each user.
This may seem to be a rather simple question, but my adviser does not seem convinced that the above understanding is completely valid.
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Dear Abdullah,
welcome!
The answer of your question is that so long as the channel condition is not changed there is no cause to change the most suitable modulation order. So, all the subcarriers in this time where the channel is fixed will be modulated by the same QAM order.
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While building private LTE networks for industries/mines, how will they connect to Internet? Is it obligatory to connect via an mobile operator or what are the options we have to connect to internet break out?
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Dear Karthik,
You need to add in the core of the network , a packet data network PDN gateway.
The PDN gateway connects UEs to an external PDN. This network component connects the the Serving gateway (SGW) to the IP network.
The SGW routes and forwards data packets and manages user mobility as well as mobility between LTE and other 3GPP technologies.
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According to 5G NR Frame Structure, the frame is divided into sub-frames and each sub-frame is divided into slots and each slot has 14 OFDM symbols (for a normal cyclic prefix). Number of slots per sub-frame varies according to numerology. There are multiple OFDM numerologies based on the bandwidth available.
Now my question is, With this flexibility in deciding the slots per sub-frame, How the numerology is changing? Like is it changing OFDM symbol-wise or Slot-wise or Sub-frame wise or is there anything else?
Thanks in Advance
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In the time-domain, the change of numerology can be done at the sub-frame level.
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The Definition of RSSI is 'Total received wide-band power by UE'
1. I have confusion in understanding that what is meant by wide-band here.
My understanding is as follows
  • In case if Carrier Bandwidth of LTE channel is 10 MHz,total bandwidth is 10 MHz and hence RSSI is calculated for all the all the Resource blocks i.e. 50 RB
  • Each RB has 12 subcarriers. Hence for 10 MHz channel, 50 RB are dedicated => 12x50 = 60 subchannels
  • Finally (Assuming same Pt for all subcarrier) Pr = Pt*(c/4*pi*d*F*)2 . What is the F should I put and is this the right way to calculate the Pr? In my opinions F = 15KhZ. Where Pr is Received Power per subcarrier by UE. (Using 
  • Finally RSSI = Pr*12*50  [ or dBm 10*log10(Pr) + 10*log10(12*50) ]
2. Or RSSI is calculated in any different way in simulation / How can I make simulation model to calculate RSSI. Do I have to make a model with a complete RB with all Resource Elements (RE). If yes, then do I need to do the scheduling as well?
3. How can I calculate SINR with RSSI?
Thanks
Shan
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If you have found your answer by now, please let me know.
I do have the exact same problem regarding the choice of frequency to calculate RSSI.
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I am new to in NS3. I am working on LTE networks. I was looking for calculation of Load information of each cell and exchange of the same between eNBs (over X2 interface/ based handover). Could any one please help me with pointers to code, or if you already have the code snippet.
I did search through the docs. But still needed some additional help. Could you please help me.
Is it possible to calculate the number of RBs allocated to the UE in NS3?.
Thank you.
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Thank you for all the answers. I will read through the materials.
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I wonder which simulator is more suitable for implementing routing protocols in D2D communication in LTE/ LTE-A network?
Most of the simulators are focused in link-level (e.g VIENNA and other Matlab based simulators)
I need a system-level simulator for my research, and it seems the top alternatives are SimuLTE from OMNET++ and LENA from NS3.
Thanks for sharing your experiences
Kindest wishes
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Dear.
I suggest you investigate the https://apps.nsnam.org/app/publicsafetylte/ for ns-3.
Cheers.
--E
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Why 3GPP combined S-GW and P-GW in LTE to one component SGW-PGW in 5G mobile network?
The figure shows the Serving Gateway and PDN Gateway of LTE. These two components have been combined in 5G for a reason related to IP impairments and signaling issues.
Any idea or link that clarifies this point?
I was reading this paper "Ultra-Reliable Low Latency Cellular Networks:
Use Cases, Challenges and Approaches" but I couldn't find the exact answer. Which causes the delay? Is it the Serving GW or PDN GW, and why?
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TLDR;
They are not merged, a new Service based Architecture is proposed with modular Network Functions (NFs).
Details:
In 5G, all the naming of the NFs is revisited in order to address the Service Based Architecture approach (SBA) proposed to address functions modularity and service oriented designs.
For example: The former Mobility Management Entity of 4G (MME) that used to take care of Session Management is handled by a new NF in 5G, called Session Management Function (SMF).
Furthermore, Packet routing and forwarding that used to be handled by the Serving and Packet Gateways (SGW and PGW) in 4G, are handled in 5G by an NF called User Plane Function (UPF).
For details on the SBA, Please refer to 3GPP TS (23.501 and 23.502).
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When Carrier Aggregation and cross-carrier scheduling are applied in LTE-Advanced system, UE may support multiple Component Carriers (CC) and control information on one CC can allocate radio resource on another CC. Search space of all CCs and control information is only transmitted from a chosen CC. In this case, if search spaces of different CCs are not properly defined, high blocking probability of control information will be very harmful to system performance.
My Question is: What is the cause of this blocking, is it deficiency of control channel elements to served, scheduled UE or what?
My guess is not but I have no proof of this. Can any expert help?
For now, I assume either self-overlapping or high mutual over-lapping of the UEs' search spaces as the likely cause of blocking.
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The main responsible guys behind Blocking users are Available CCEs and the Schedular one design to get the user fit into this If the hash function gives the indices which are already occupied then user can't get scheduled resulting in getting blocked. I hope the mentioned point makes sense to understand the reason for blocking users. Kindly refer to this to understand clearly.
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When Carrier Aggregation and cross-carrier scheduling are applied in LTE-Advanced system, UE may support multiple Component Carriers (CC) and control information on one CC can allocate radio resource on another CC.
search space of all CCs and control information is only transmitted from a chosen CC. In this case, if search spaces of different CCs are not properly defined, high blocking probability of control information will be very harmful to system performance.
My Question is: What is the cause of this blocking, is it deficiency of control channel elements to served the scheduled UE or what?
I guess is not but I have no prove for this. any expert can help?
for now, I assume either self-overlapping or high mutual over-lapping of the UEs' search spaces might be the cause of blocking.
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It depends on the availability of CCEs(Contol Channel Elements) in a given subframe. When all available CCEs get filled and the UEs don't find any location to get scheduled that is the case arrived of blocking. I hope this answer helps you to understand for more details kindly go through the paper once
https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7382423 (Scattered Search Space Scheme for PDCCH and ePDCCH in LTE-Advanced).
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I have gone through 3GPP TS-38.211, 212, & 213 of the Downlink part I couldn't able to gather the info of the Number of NR-PDCCH blind decoding calculation. If anyone has understood that kindly explain the calculation.
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Hi.,
The UE finds the PDCCH specific to it by monitoring a set of PDCCH candidates (a set of consecutive CCEs on which a PDCCH could be mapped) in every subframe. The UE uses its Radio Network Temporary Identifier (RNTI) to try and decode candidates. The RNTI is used to demask a PDCCH candidate's CRC.
For more info:
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I read somewhere that 23 dBm power is used for uplink transmit in LTE. I wanted to understand that is this power to transmit on the whole channel or is it for few bits? also I wanted to know how much power would be required to transmit a Sounding Reference Signal in uplink direction?
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The power can be divided over all or a subset of the subcarriers, leading to different SNRs at the subcarriers. What matters when sending sounding reference signals is that received SNR is sufficiently high to enable demodulation.
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According to 3GPP standards "3GPP TS 36.211 version 13.2.0 Release 13" in section 10.1.6:
"The preamble consisting of 4 symbol groups transmitted without gaps shall be transmitted NPRACHrep N times"
Does the mentioned "without gaps" means only for one preamble itself, it should be transmitted without gaps? (all 4 symbol groups one after another without time gaps)
Or does it means all repetitions should be transmitted one after another without any gaps in between?
This question arises as many papers consider the second case (no time gaps between all repetitions). However, this is against the standards which mentioned clearly in the same section:
"The transmission of a random access preamble, if triggered by the MAC layer, is restricted to certain time and frequency resources.
NPRACH transmission can start only NNPRACHstart ⋅30720T time units after the start of a radio frame fulfilling nf mod( NNPRACHperiod /10)=0"
This means that NPRACH happens only in certain frames fulfilling mentioned conditions. Thus, preamble repetitions can be transmitted only in those frames. which means it can't be transmitted continuously without gaps because we can never have two consequent frames which fulfil the condition.
The attached figure shows which frames in time domain do have NPRACH.
Kindly, if my previous notation is wrong and repetitions should be transmitted continuously without gaps can you explain to me how that comply with the standards especially with "NNprachPeriodicity"?
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Dear Anas,
The function of the preample is for timing and synchronization in addition to channel estimation. So, the preample symbols must be sent continuously without interruption inside the preample. As for the preamble itself it is sent whenever one needs to send it to synchronize data and assess the channel. It depends on the channel conditions.The preamples must not sent periodically.
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I'm working on a project where I've decreased the transmission of SRS (Sounding Reference Signal) which would vacate 6 REs in a subframe. So, how much will much will this increase our throughput?
Regards,
Ruzat Ullah
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The same contains two time slots. Each time slot contains two resource blocks. Every resource block contains 7 symbols x12 subcarriers= 84 resource element.
So each subframe contains 168 resource element.
If you vacate 6 RE per subframe then you increased the throughput by about 6/ 168. You can exactly calculate the data pay load RE say REpl and refer the the 6 to them. You will get more improvement.
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I have used a LTE simulator to get a selected resource block occupancy state, and I have used the output as an train and test data to predict idle or busy state of selected RB using MLP. but in order to check my results, I need to simulate primary user traffic on a channel which following Poisson process and also the ON/OFF time of channel should be drawn from geometric distribution. does anyone have a Matlab code simulating this traffic model?
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Dear friends,
am executed but displayed error message for below manner how to rectify that
error: 'in' undefined near line 3 column 4 error: execution exception in main.m
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I need details on how RSRP,Velocity and TTT is calculated in LTE Handover
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thanks akash
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Physical layer (PHY) authentication based on the unique channel properties has proven effective due to its simple, fast, and distributed procedures with the recent explosion of the Internet of things (IoT) devices. Authentication is the process of verifying identity claims. If an intruder collects confidential information on wireless links and sends a forged signal, it can cause serious problems. Through an authentication protocol, which verifies the identities of both parties over the wireless link and then establishes a common secret key between them, these threats can be reduced or even completely eliminated. Consistently the conventional cryptographic security mechanisms have been used to prevent intelligent attacks (e.g., impersonation attack). Although the effectiveness of these cryptography-based authentication mechanisms have been proven, proper key management and distribution which may cause large signaling overhead in a large scale network (e.g., Internet of things (IoT)) are required.
Papers:
J. Choi, ”A coding approach with key-channel randomization for physical-layer authentication,” IEEE Trans. Information Forensics and Security, vol. 14, pp. 175-185, Jan 2019.
X. Wu, Z. Yang, C. Ling, and X-G. Xia, ”Artificial-noise-aided physical layer phase challenge-response authentication for practical OFDM transmission,” IEEE Transactions on Wireless Communications, vol. 15, no. 10, pp. 6611-6625, Oct. 2016.
X. Wu, and Z. Yang, ”Physical-layer authentication for multi-carrier transmission,” IEEE Communications Letters, vol. 19, no. 1, pp. 74-77, Jan. 2015.
X. Du, D. Shan, K. Zeng, and L. Huie, ”Physical layer challengeresponse authentication in wireless networks with relay,” in Proceedings IEEE INFOCOM, Toronto, ON, Canada, Apr. 2014, pp. 1276-1284.
J. Cao, M. Ma, H. Li, Y. Zhang, and Z. Luo, ”A survey on security aspects for LTE and LTE-A networks,” IEEE Communications Surveys & Tutorials, vol. 16, no. 1, pp. 283-302, 1st Quart., 2014.
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hi,
The near real-time processing of continuous data flows in large scale sensor networks .. it is used to classify the data whether it is real time or non-real time traffic ... A Public Key based Encryption and Signature Verification Model for Secured .. This innovation will pave the way to the development of new .... IoT technologies may be also adopted in the industry for real-time monitoring .... This API also requires API Keys for authentication and exchanges information in JSON format. .... Sensor devices and physical objects belong in it Network layer ..
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Is there any code for eNB (for LTE) that could be run on an OpenWRT Linux to emulate eNB in a test-bed environment?
Please help.
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Dear
Muhammad Dzakwan Falih
Thank you for your valuable notes.
Regarding Note number 3, I think you mean srsLTE, is that right?
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I am trying to simulate a C-RAN system by interfacing cloudsim with an LTE simulator. Any guidance on the matter would be appreciated ! Thanks.
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Surender Singh @ Dear sir i am working on cloud RAN and i go though the link you provide, at present this link is not working, so is there any other option to simulate C-RAN on java
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TCP is transmission control protocol
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Dear,
you can read this paper:
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Is it OK to dilute a DNA extract with UltraPure sterile water?
I was trying to measure sample concentration with a Qubit 3.0 Fluorometer , but the readings were too high and I needed to dilute my sample. So, I diluted my DNA extract with UP water and then repeated the Qubit assay. I am wondering if I should have used a LTE buffer instead of the UP water to dilute my samples.
Thank you!
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Dear Christina, we use sterile ultrapure water to dissolve or dilute DNA samples. It is suitable to dilute.
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I am analyzing the complexity of resource allocation problems in NOMA systems. The network model is shortly summarized as: a base station (BS) and multiple users (UES), singles for all UEs are superimposed at the BS, and the objective is to allocate at the BS so that optimize the resources. In addition, I am using the network sum-rate maximization is a baseline, which is NP-Hard according to my own finding. However, I am not sure about this (NP-Hardness of the sum-rate maximization problem).
Does anyone have any suggestions for me?
Many thanks in advance.
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Most of works are relating to downlink NOMA. For uplink NOMA, different system model and problem formulation should be considered.
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Hello RG.
Can a position/distance error be represented as frequency error or Doppler in antenna systems?
Thanks in advance.
Regards
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Dear Mohammed,
The distance traveled by an electromagnetic wave L = c t where c is the velocity of light and t is the propagation time. If these is an error in the distance then there will be an equivalent error in time dt such that dL=c dt. Accordingly, this will be equivalent to statistical variations of the symbol arrival time. From this simple thinking, one can treat statistical distance errors as statistical delay time in the symbol time. Most probable it will cause statistical delay errors that may cause inter symbol interference.
Frequency offset requires a change in the rate of change of the propagation distance with time.
Best wishes
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What is the difference between MCS and CQI?
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Dear Fadi,
welcome,
The modification and coding techniques are characterized by what is called bit error rate BER versus the signal to noise and interference ratio. Everu modullation and channel coding technique has a specific BER versus energy per bit to noise density ratio. These curves are used to determine the minimum required S/N density ratio for certain quality of service expressed in an an upper bound of bit error rate.
As for the the CQI it is the channel quality indicator which is the measured S/N ratio at the receiver under specific channel condition and at specific time. It is used to adopt the coding and modulation to the channel state.
Best wishes
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I have a table which show the code rate and efficiency of MCS index 0-28.  However, it is only for LTE downlink.
Anyone know  the efficiency of a given MCS index for LTE uplink?
Thank you very much!
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Hello Can someone explain me how to analyse these curves of MCS?
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Hello!! I have some questions regarding the effects of physical parameters over a UE battery usage. I want to know that what are the factors which increase a user's battery drainage in LTE? What are the effects of Low SINR over UE battery? How does Low received power effects ? Distance from a BS ?? Data size and data rate play any role over battery ?? Or any other factors which need to be controlled for Battery Efficiency.
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Hello!
In summary, when a UE try to access the BS by transmitting Random access Preamble (RACH), it must receive an acknowledgement from the BS and uplink synchronization must be done. But, for some reason (distance or collision between two UE's RACH) the UE doesn't receive the acknowledgement, it will transmit perform the RACH again after waiting for some specified time. Again, if it doesn't receive the acknowledgement then it will increase the power to compensate the power loss. This is just one example. There are many other parameters that can effect the battery of the UE. Like, handover, data rate, etc.
Have a look at these papers:
LTE UE Power Consumption Model: For System Level Energy and Performance Optimization
Analyzing mobile applications and power consumption on smartphone over LTE network
Battery life idle parameter optimization of UE in self organizing network
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hello My name is Fady Dawra and I need a help about the algorithm of the scrambling mentioned in LTE. I need an explication of the first 2 cases in the algorithm please.
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i'm using ns-allinone-2.31(under Cygwin), and i want to simulate the LTE(4G) in my framework to represent a wireless cellular network. How can i do it?, and what do i need to download? Best regards.
saleh
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interested
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Different companding methods such as μ-law, hyperbolic tangent, exponential, linear symmetric transforms, linear asymmetric transforms and threshold log companding are used for PAPR reduction in OFDM.
Is there any other efficient companding methods?
Besides, is there any other method of PAPR reduction in OFDM except companding?
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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
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In the legacy LTE network, the Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS) are transmitted once (each of them) every 5ms i.e. in subframe 0 and subframe 5 . But a pair of Primary Side link Synchronization Signal (PSSS) and a pair of Secondary Side link Synchronization Signal (SSSS) are transmitted in the sidelink synchronization subframe in case of D2D or v2x communication. But I am not clear why.
Thanks in advance.
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Dear Merkebu,
welcome!
I would expect that the channel conditions D2D and V2X is more serve than the channel conditions in conventional mobile communication systems. The multipath fading and the fast fading due to doppler effect may be more pronounced in such communication channel. Which means higher rate change of the channle with time. Consequently the frequency of the synchronization signal must be increased.
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Long Term Evolution (LTE) is the 4th generation broadband technology for mobile. LTE has been developed by 3GPP in release 8 technical specifications (R8). The LTE facilitates QoS to be guaranteed through EPS and Quality of service class identifier (QCI).
Papers:
ETSI TR 102 805-1 V1.1.1: “User Group; End-to-end QoS
management at the Network Interfaces; User's E2E QoS -
Analysis of the NGN interfaces (user case)”.
ETSI TS 103.189: “End-to-end QoS assessment for VoLTE and RCS Interop Events”.
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For VoLTE you're late, it's done. For 5G QoS you're early, but there are early deployments to watch.
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Can any one explain how the number of PRACH slots within a sub-frame value is obtained in 5G NR?.
In 3GPP 38.211 v15.1.0-Table 6.3.3.2-2 <Random access configurations for FR1 and paired spectrum/supplementary uplink >, it is mentioned that the number of PRACH slots within a sub-frame is either 1,2 or ''-", depending on the preamble format.
Does the value "2" means that there are two slots available for one preamble transmission? or is it two slots for two different preamble transmission opportunities?.
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