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5G
As the world becomes more and more connected, the demand for faster, more efficient wirelesss communication grows. Especially with the rise of intelligent things operating in the physical world, advanced cellular IoT modems are more critical than ever.
Without a cellular modem, smart devices could not connect to LTE or 5G networks. Its hidden technology is what enables high-speed mobile data, low-latency communication and global wireless connectivity.
How is this Connection Possible?
It all starts with the mobile networks...
Mobile networks are formed by Base Stations deployed across the globe. Each Base Station covers a circular area called a cell - which is why LTE and 5G are referred to as cellular networks. Within these cells, Base Stations wirelessly connect with smartphones, vehicles, and even industrial robots. This enables communication via electromagnetic signals in the radio frequency spectrum that carry information both to and from the mobile device.
At the heart of a mobile device there is a modem, the integrated system that translates digital application data into radio frequency (RF) signals and vice versa. This process called modulation and demodulation enables applications to send and receive data wirelessly.
How do Modems Work?
A modem is essentially built from three electronic subsystems that work together: the RF, the Analog Base Band, and lastly the Digital Base Band with embedded Protocol Stack firmware. Each plays a specific role in ensuring that data can be received (RX) and transmitted (TX) reliably across wireless channels.
The RF
The RF is the first and last stop for radio signals entering or leaving a cellular IoT modem. It manages the physical interface to the antenna, using filters, switches, duplexers, low-noise amplifiers (LNAs), power amplifiers (PAs) and mixers to prepare signals for radio transmission and clean up incoming ones.
In the receive path, a Filter removes unwanted frequencies and a LNA amplifies weak signals without adding noise. A Mixer down-converts received high-frequency RF signals into low-frequency base band signals by mixing it with a local oscillator (LO) clock.
On the transmit path, after the frequency up-conversion by a Mixer, a PA boosts the transmit signal to the appropriate power level — especially critical at the edges of a cell — and ensures together with a Filter compliance with wireless emission standards.
The Analog Base Band
The Analog Base Band is the essential subsystem that acts as the bridge between digital intelligence and analog radio communication. This involves filtering out unwanted frequences through analog baseband filters with gain stages adjusting the amplitudes.
In the receive path, analog signals from the filter stage are digitized by high-speed Analog-to-Digital Converters (ADCs) through sampling and discrete quantization. The resulting digital symbols are provided to the Digital Base Band for digital signal processing.
In the transmit path, the digital symbols from the Digital Base Band are converted by high-speed Digital-to-Analog Converters (DAC) into analog base band signals before they reach the filter stage.
The Analog Base Band
The Analog Base Band is the essential subsystem that acts as the bridge between digital intelligence and analog radio communication. This involves filtering out unwanted frequences through analog baseband filters with gain stages adjusting the amplitudes.
In the receive path, analog signals from the filter stage are digitized by high-speed Analog-to-Digital Converters (ADCs) through sampling and discrete quantization. The resulting digital symbols are provided to the Digital Base Band for digital signal processing.
In the transmit path, the digital symbols from the Digital Base Band are converted by high-speed Digital-to-Analog Converters (DAC) into analog base band signals before they reach the filter stage.
The Digital Base Band & Protocol Stack
The Digital Base Band & Protocol Stack is where the real digital magic happens. It’s responsible for transforming raw application data — like sensor readings or video streams — into packets of digital symbols that the Analog Base Band and the RF can handle, and vice versa.
In the receive path of the Digital Base Band, the digital symbols are processed by the Physical Layer 1 (L1-PHY). Here, advanced algorithms perform demodulation and signal decoding. In the transmit path, L1-PHY modulates outgoing data depending on the wirless channel state before passing them to the Analog Base Band.
The Protocol Stack, with Layer 2 for error correction and framing and Layer 3 for data routing and IP addressing, ensures robust and secure transmission across the mobile network. This layered digital architecture allows cellular IoT modems to support reliable wireless communication over global 5G and LTE networks — making them the backbone of scalable, intelligent IoT systems.
Empower the Future of Cellular IoT with bridgecom
Bridgecom provides complete cellular IoT modem platforms comprising of Base Band processors (BBIC) with embedded Protocol Stack firmware and advanced RF Transceivers (RFIC) combined with third party RF front-end components. Our cellular IoT modems can be trusted to deliver reliable, low-power connectivity in the world’s most demanding environments enabling the next wave of cellular-connected intelligence.
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