Questions tagged [telecommunication]

Use this tag for questions about communications technology and its applications.

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1answer
120 views

How does 4G know the reception of a voice call?

I know that the 4G network is only for data and doesn't support voice calls. Most of phones switch to 2G/3G when receiving a voice call. But my problem is how does the phone gets to know about the ...
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0answers
30 views

How does the demapping/demultiplexing of transport channels to logical channels work?

I am trying to model WCDMA MAC, but I cannot figure out how to demultiplex HS-DSCH unto DCCH, DTCH. Also, since I am using E-DCH/HS-DSCH transport channel scheme, how does the data of DCCH and DTCH ...
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1answer
46 views

Sending SMS using car horn [closed]

If you've been watching Bones series, there is an episode in which Bones and Hodgins were trapped beneath the ground, and they managed to send an SMS by wiring the phone to the car honk. Is this ...
5
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1answer
2k views

Why do bluetooth headsets get interference (choppy sound quality) outdoors?

This is more of a general physics question to help me understand how to choose sports headsets in the future, however it is too specific to a certain use case (bluetooth headset) to belong in the ...
2
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1answer
121 views

Why is WiFi increasing frequency?

WiFi at 60 GHz provides a theoretical data-rate of 7 Gbit/s. The trade-off is limited range and penetration. The main reason for this awesome data-rate is a 9 GHz bandwidth, from 66 GHz to 57 GHz. I ...
2
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1answer
349 views

A 40MHz oscillator in usb wifi adapter

I disassembled a usb wifi adapter. I was surprised to see a 40MHz oscillator, when wifi works at 2.4GHz. How the output of the oscillator is scaled to the required frequency?
0
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2answers
107 views

How can I make a GPS traceable microchip? [closed]

I am looking for making a chip or a microchip, which can be traced with the help of the satellites. Means it is merely a chip and when I tune my satellite to a particular frequency I would get to know ...
2
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3answers
204 views

Why not only GSM (3G/4G/..)? Why do we need Bluetooth, Wifi,etc…?

It is quite frustrating to have multiple adapter for connecting to desktop. For example, if I want to connect my phone to desktop I need Bluetooth/wifi; why can't I just just use the Mobile's main ...
2
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0answers
54 views

Effect of bad weather on P2P Communication or Broadcasting?

I stop receiving TV signals whenever their is cloud cover outside. On the other hand I have never had any such problems with my internet connection or GPS system. I cannot understand why and how often ...
3
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0answers
132 views

How is modulated the Primary Synchronization Signal in LTE?

PSS is based on 62 values from a Zadoff-Chu sequence. Three different sequences can be used by an LTE Cell, to represent the Physical Cell ID within the Cell ID group. The formula is the following, $...
1
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1answer
67 views

Will the water in a gold fish bowl signficantly abosorb Bluetooth or WiFi if transciever is at bottom of bowl?

Using WiFi or bluetooth frequencies 5.8GHz and 2.4-2.485GHz respectively, I want to place a hermetically sealed circuit at the bottom of a gold fish bowl, and want to know if the water will ...
4
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0answers
181 views

LTE channel characterization from Time Domain waveform

I am currently interested into the diverse Downlink LTE channels broadcasted over air after some (QPSK, 16QAM...) modulation. More precisely their waveform. I would like to know if, with a good ...
3
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0answers
45 views

What is PSS waveform formula?

I want to know how is exactly modulated a LTE subcarrier. Since I'm working on Synchronization Signals (P-SS, S-SS) the subcarriers I'm talking about are centered around DC. I have coded the ...
3
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1answer
2k views

What are the pros and cons of between Zigbee and Z-Wave communication protocols used in IoT device space?

Recently, both Zigbee and Z-wave tend to be the most commonly used protocol to communicate between Internet of Things (IoT) devices. Most of these IoT devices tend to have a combination of mechanical ...
6
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0answers
540 views

How does LTE eNodeB set the Base Station output power?

I'm interested into the power radiated out of an eNodeB (LTE/4G) radio base station: which parameters does this power depend on, if they are constant or relying on the environment... All of this in ...
3
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0answers
107 views

FM transmission exercise

I'm encountering some troubles while trying to solve this exercise. Let us consider a radio link between a geostationary satellite and a ground station. We send a binary signal (represented by two ...
2
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1answer
116 views

Why is Li-Fi faster than regular wifi?

I was wondering, basicly every radio-transsmission works with electromagnetic waves which travels at the same speed whether I modulate the information with a low frequency or high frequency such as ...
2
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1answer
197 views

Hilbert transform LTI

I'm studying the Hilbert transform and its properties. I found out that Hilbert transform can be considered as a linear time-invariant system. How can I show this? I guess this should be trivial as ...
2
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1answer
42 views

What is the thinnest possible depth of any given material required to display an image? [closed]

I am interested in creating a screen to display moving images (similar to moving desktop background), however I am looking for the thinnest possible material available i can use as the screen to ...
0
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1answer
570 views

How far can my FM transmitter signal reach?

I have a working FM transmitter on a raspberry pi2. I'm running my FM raido at 103.3MHz, and the antenna that I connected to the GPIO4 is a 70cm copper wire. More data:(checked with a multimeter ...
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1answer
102 views

how to calculate the time for retransmission in slotted Aloha

I need to configure my code to make retransmission in slotted Aloha in case of collision, how to choose the timer ?
12
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4answers
788 views

Is interference between aircraft an issue for fly-by-wireless technology?

I was reading up on fly-by-wire development, and I saw a short section about fly-by-wireless technology. It seems like a great idea, with the potential to lower costs, weight and complexity. I can see ...
3
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1answer
919 views

signal-to-interference-plus-noise ratio (SINR) and others calculation

I am considering some empirical signal propagation models (like Hata, Ericsson models) to calculate 4 parameters: Path loss Received Signal Strength (RSS) signal-to-interference-plus-noise ratio ...
2
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1answer
87 views

How does a carrier signal work from a receiver's perspective?

for example : Sender: A cellular signal tower(Base Station(BS)) sends data(voice, GPRS, VOIP) to the cellphone. The sender will obviously have the carrier frequency and more power(voltage+current) to ...
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1answer
27 views

Could a one sensor node in a cluster sense a data more the others?

I want to know if the sensor nodes in any cluster in a wireless sensor network may detect events in a different ratio i.e.some nodes could detect events more others in the same cluster, so is power ...
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0answers
1k views

seeking help for decoding a call log / PCHR trace files (Call logs)of Huawei V900 R015 machine(.log files) [closed]

I have PCHR trace files of the above mentioned server . But unfortunately I couldn’t find an appropriate decoding software to read those files. I tried manual through a c program but it didn’t work ...
7
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0answers
524 views

BER peroformance of MPSK and MQAM in Rayleigh fading channel

I have a question regarding bit error rate (BER) performance over the Rayleigh channel. I observed BER performance over the AWGN channel using Simulink in MATLAB. I used to change the "SNR" parameter ...
2
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1answer
2k views

What kind of signal is the signum function? A power signal or an energy signal?

I'm studying "signals and systems". We can indentify two kinds of signals: power signal and energy signal. The definitions are: Energy of a time-continous signal $$ E_x = \int_{-\infty}^{+\infty}{|x(...
1
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1answer
132 views

How to join between two PBX telephones wirelessly?

I have two PBX telephones. Each one has a line cables to the houses, but there is no connection between these two pbx telephones, neither wire nor wireless. How can I join between them wirelessly? ...
3
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0answers
53 views

Viability of creating a wireless LAN bridge between mobiles and PCs using a portable router? [closed]

I am creating a network to share files between a mobile device and multiple PCs directly through a LAN. The purpose of which is to use smart phones to capture files from remote devices which are ...
3
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0answers
49 views

Wifi modulation and standard interoperability

I've been reading this summary(info.tek.com) of Wifi standards from Tektronix, which seems to do a pretty decent job of explaining things, but has left me with a couple of questions: For access ...
8
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3answers
543 views

Protecting device from microwaves in microwave oven.. but allowing Bluetooth?

I am building a device that needs to be inside of a microwave oven but somehow needs to communicate with another device outside of the microwave. How can I reflect microwaves so they don't come into ...
2
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2answers
249 views

Control RF wave direction or path

I have a rf module transmitting from an antenna. As you see in Figure 1, I have a radio mast that sends waves in all directions. I don't want this. My plan for controlling wave direction is Figure 2. ...

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