engineering

Remote radio head

Remote radio head is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Remote radio head rather than just read about it. In short: A remote radio head (RRH), also called a remote radio unit (RRU) in wireless networks, is a remote radio transceiver that connects to an operator radio control panel via electrical or wireless interface. When used to describe aircraft radio cockpit radio systems, the control panel is often called the radio head.

Key takeaways

Remote radio head belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Remote radio head to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Remote radio head from memory before moving on to harder problems.

Reference excerpt

A remote radio head (RRH), also called a remote radio unit (RRU) in wireless networks, is a remote radio transceiver that connects to an operator radio control panel via electrical or wireless interface. When used to describe aircraft radio cockpit radio systems, the control panel is often called the radio head. In wireless system technologies such as GSM, CDMA, UMTS, LTE, 5G NR this radio equipment is remote to baseband units such as BTS/NodeB/eNodeB/gNodeB or gNB. This equipment is used to extend the coverage of a baseband unit in challenging environments such as rural areas or tunnels. RRHs are generally connected to the baseband unit or base station which can be an x86 server on the ground near a cell tower, via a fiber optic cable using Common Public Radio Interface protocols. It can also be a dedicated radio unit.

RRHs have become one of the most important subsystems of today's new distributed base stations. The RRH contains RF circuitry plus analog-to-digital/digital-to-analog converters and up/down converters, and connects to, and thus drives the cell site's antenna. RRHs also have operation and management processing capabilities and a standardized optical interface to connect to the rest of the base station/baseband unit. This will be increasingly true as LTE and WiMAX are deployed. Remote radio heads make MIMO operation easier; they increase a base station's efficiency and facilitate easier physical location for gap coverage problems. RRHs will use the latest RF component technology including gallium nitride (GaN) RF power devices and envelope tracking technology within the RRH RF power amplifier (RFPA).

RRH protection in fiber to the antenna systems Fourth generation (4G) and beyond infrastructure deployments will include the implementation of Fiber to the Antenna (FTTA) architecture. FTTA architecture has enabled lower power requirements, distributed antenna sites, and a reduced base station footprint than conventional tower sites. The use of FTTA will promote the separation of power and signal components from the base station and their relocation to the top of the tower mast in a Remote Radio Head (RRH). According to the Telcordia industry standard that establishes generic requirements for Fiber to the Antenna (FTTA) protection GR-3177, the RRH shifts the entire high-frequency and power electronic segments from the base station to a location adjacent to the antenna. The RRH will be served by optical fiber and DC power for the optical-to-electronic conversion at the RRH. RRHs located on cell towers will require Surge Protective Devices (SPDs) to protect the system from lightning strikes and induced power surges. There is also a change in electrical overstress exposure due to the relocation of the equipment from the base station to the top of the mast.

Protection from lightning damage RRHs can be installed in a low-profile arrangement along a rooftop, or can involve a much higher tower arrangement. When installed at the highest point on a structure (whether a building or a dedicated cell tower), they will be more vulnerable to receiving a direct lightning strike and higher induced lightning levels, compared with those installed in a lower profile manner below the upper edges of the building. As noted in GR-3177, while surges can be induced into the RRH wiring for lightning striking the nearby rooftop or even the base station closure, the worst case will occur when a direct strike occurs to the antenna or its supporting structure. Designing the electrical protection to handle this situation will provide protection for less damaging scenarios... it can also be use in optical fiber communication but different type.

See also Cell site Cellular network Telecom infrastructure sharing OpenBTS Wireless device radiation and health Radio Common Public Radio Interface Radio access network

References

External links http://www.cpri.info

Illustrations

Worked examples

Example 1 — a first encounter with Remote radio head

Start with the simplest possible case. Write down what Remote radio head claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Remote radio head before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Remote radio head ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Remote radio head

In research: Remote radio head appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Remote radio head in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Remote radio head is common in secondary-school and first-year university syllabi. It links to neighbouring topics Mobile telecommunication services, Radio technology, Telecommunications infrastructure, so understanding it makes those chapters shorter.
In everyday life: Look for Remote radio head outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Remote radio head in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Remote radio head means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Remote radio head out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Remote radio head in simple terms?

Why does Remote radio head matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Remote radio head?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Remote radio head.