Electrical Engineering Stack Exchange
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Questions tagged [cellular]

Cellular systems are wireless communication systems. Examples are 2G systems like GSM, 3G systems like UMTS and cdma2000, and more recently, LTE and 5G.

Cellular systems are wireless communication systems. Their distinguishing characteristic is that they break down an area (such as a city) into cells. Each cell is served by a base station. We can imagine cells to have hexagonal coverage areas, and then the large area can be neatly broken down into these hexagonal coverage areas.

Examples are 2G systems like GSM, 3G systems like UMTS and cdma2000, and more recently, LTE and 5G.

Use this tag on questions related to any aspects of cellular systems.

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Simulate bad cell phone reception in the lab

I'm currently developing an internet of things device that utilizes a uBlox SARA-U260 gsm/3G modem. In field testing, we have had significant software/firmware issues due to poor cell phone reception in our deployments in sub-saharan Africa. I'm…
macdonaldtomw
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5G and Radar Altimeter Interference - Am I Taking Crazy Pills?

I can't understand where the math supports the concept of 5G frequencies interfering with aircraft altimeters. Can anyone point out the holes in my logic or educate me? Knowns: Aircraft altimeter frequency range: 4.2 - 4.4 GHz Closest 5G…
1337_Pawn
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SIM808 registration denied for new SIMs

I have a SIMCom SIM808 2G GSM module on a custom PCB based upon the Adafruit FONA. I got a bunch of 2G SIM cards from Aeris.net. The problem is when I first put the SIM cards in my device, I get "Registration Denied" (+CREG: 3) and the device will…
skot9000
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Arduino Cellular Shield EMC Testing for FCC

I have designed an Arduino shield that uses an FCC pre-certified and PTCRB cellular module and I'm wondering about EMC testing and FCC compliance. However, the main concern here is that I am using a different antenna and I read that I have to use…
arduinofanboy
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What is the difference between capacity and throughput in context of wireless/cellular communication?

From what I understand: Throughput tells you how much data was actually transferred from a source at any given time Bandwidth tells you how much data could theoretically be transferred from a source at any given point Capacity is the maximum…
Aditya Saini
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What are the units used in Shannon formula calculation?

I'm a CompSci student with absolutely no background in wireless communication who recently needs to do something with the Shannon formula: $$ R = W log_2\bigg(1+\frac{P_t H^2}{N_0 W}\bigg) $$ I need to calculate the achievable data rate \$R\$…
foo
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Intel Compute Stick & USB 4G Device

Id like to create a powerful IoT Edge device that has cellular capability (Wifi is undesirable). Right now the intel compute stick/neural stick almost fits the bill except that it does not have 4G capability. So what id like to do is buy a compute…
Ace
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Top Ground Copper pour in PCB having three RF Sections

I am designing my second RF board (First one had BLE). This board has LoRa Components (SX1257 and SX1301), GPS (MAX-6) and 4G LTE Module (SIM7600). All the components are on top layer (red layer). My STACKUP is: Layer 1 (Red): Signal layer with…
abhiarora
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SIM7600A gives an error when executing commands, but works after executing it again

I am currently using a WaveShare cellular modem hat for my Raspberry Pi. The module has an onboard SIM7600A. I've been reading the documentation and although all the commands work as they are supposed to, some commands fail when I try to execute…
Trevin Corkery
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Why do baseband processors remain on, and communicating with the tower, when the phone is shut down?

I've believed this since 1994 - that if you really want to turn off a cell phone, you need to take the battery out. But why? What is a good technical reason to keep spending battery charge and occupying tower bandwidth despite the user having shut…
Todd Messenger
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Cellular module(4G/3G/GSM) interface to host processor or microcontroller through UART how the data rate is achieved?

The majority of cellular modules are interfaced to host microcontrollers or microprocessors using UART interface or some times USB interface (where internally it's UART). But the data rate of UART is much less. How are we able to achieve cellular…
Prashanth Kumar G N
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Accidentally connected a GPS antenna to a cellular connector and a cellular antenna to a GPS port. What can go wrong?

I have two ultra small/sub-miniature coaxial connectors on my circuit board - one for a cellular (4G) antenna and one for a GPS antenna. I accidentally connected the cellular antenna to the GPS connector and the GPS antenna to the cellular…
Ben N.
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Transmitter and Receiver antennas in mobile phones

I understand that in old cellular systems where FDD were employed, we used to have same antenna at the mobile phone (User equipment) for transmission and reception.Moreover, a duplexer was used to separate them. In modern cellular systems (Say, 4G…
wanderer
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Ground plane for a GSM spring antenna with 4 layer PCB

We are looking to build a 2G GSM based device with a helical spring antenna like this. The work in progress layout is as shown below: We are using a 4 layer PCB with top layer for signal, inner 1 layer for GND, inner 2 layer for power and bottom…
EarthLord
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4G Cellular Antenna

I have a Huawei E3372H-153 USB 4G dongle. It has two external antenna ports. What I want to know is that how can I make the full use of those two antenna ports to get the best 4G reception possible? Should I connect two separate antennas to those 2…
Iresh Dissanayaka
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