# 5G Overview
###### tags: `IVC O-RAN`
:::info
**Introduction：**
This note is the 5G overview, it will introduce you what is 5G ?

**You can leaned from the note：**
- 5G Performance Characteristic
- 5G Application (eMBB, mMTC and URLLC)
- 5G Technology (Spectrum, Small Cell, Massive MIMO and Beamforming)
- 5G Operation Modes
- 5G Core
- 5G Challenge (Focus on COST)
:::

https://www.techplayon.com/5g-nr-sdap-service-data-adaption-protocol/
https://www.designworldonline.com/splitting-slicing-and-disaggregating-the-ran-towards-5g/
https://www.rcrwireless.com/20200601/open_ran/who-disaggregated-my-ran

## 1. What is the 5G ?

- 5G is the global wireless standard. It’s the fifth generation wireless network following 1G, 2G, 3G, and 4G.

- 5G will elevate the mobile network to **not only interconnect people**, but also **interconnect and control machines**, **objects**, and **devices**. Thus, 5G will need to provide not only **higher throughput** but also **ultra-low latency**, **massive capacity** and **ultra-reliable** mobile network.
- So, the architecture and oriented of 5G will be different from 4G：


- It will deliver new levels of performance and efficiency that will empower **better user experiences** and **connect new industries**.
- Better user experience


## 2. 5G Performance Characteristic



### 2.1 Compare with 4G

- Network Latency：10x decrease (as low as 1ms)
- Connection Density：100x more (improving efficiency in connectivity between IoT devices)
- Peak Data Rates：20x more
- Speed：10x faster
- Throughput：10x more

## 3. 5G Application

- According to recommendation ITU-R M.2083-0 from the ITU, which has defined an international 5G vision and requirements, potential 5G services and applications can be grouped into three usage scenarios：
- eMBB (Enhanced Mobile Broadband)：5G is expected to provide much faster and **more reliable mobile broadband**, offering consumers a richer application experience.
- Peak data rate : 10 to 20 Gbps
- 100Mbps whenever needed.
- 10000 times more traffic
- mMTC (Massive Machine Type Communications)：This usage case is characterized by very large-scale or **massive applications of the Internet of Things (IoT)**.
- It supports high density of devices (about 2 x 105 in 106/Km2)
- It supports long range and power.
- It offers 10 years battery life.
- URLLC (Ultra-reliable and Low Latency Communications)：The **highest priorities** for this usage scenario are **latency** and mobility parameters.
- It offers less than 1 ms air interface latency.
- It offers 5 ms end to end latency between UE and 5G eNB.
- It is ultra-reliable and available 99.9999% of the time.

- Example of URLLC/mMTC/eMBB use case：

## 4. 5G Technology



### 4.1 5G Spectrum
The spectrum is an important component of wireless networks, especially in 5G. 5G needs the Low, Mid and High band to satisfy various applications.


- Low band (Coverage Layer)：Spectrum at a frequency **below 1 GHz** to allow 5G coverage of a large area. This spectrum can be used for **IoT applications**.
- Mid band (Capacity Layer)：Spectrum at higher frequencies, between **1 and 6 GHz**, to offer the capacity needed to assist a large number of connected devices and **allow higher speeds for devices connected together**.
- High band (High Throughput Layers): Spectrum at very high frequencies **above 24 GHz** with large bandwidth Addressing specific use case, **extremely high data rates**.
- mmWave：24.25GHz~52.61GHz (FR2)

- Spectrum of 2G ~ 5G：

The 5G cellular broadband communication network will have a relatively **large number of different cell sizes**, from macro cells to small cells. Small,or micro, cells will be for capacity boosters, and macro cells will be for ubiquitous connectivity.


### 4.2 Small Cell

According to the formula (Speed of light = frequency * wave length), the mmWave is high frequency, so its wave length is short. Thus, the **mmWave can't communicate over long distances and travel through building/obstacles**.

**Small cell is a solution to mmWave disadvantages**: inability to travel through building/obstacles and tend to be absorbed by plants/rain. Low power mini base station is used for switching to solve obstacles problem.


### 4.3 Massive MIMO (mMIMO)
- MIMO stands for **Multiple-input multiple-output**. MIMO uses **multiple antennas at the transmitter and receiver** to improve system capacity and performance.

- A Massive MIMO network will be **more responsive to devices transmitting in higher frequency bands**, which will improve coverage. **However**, Massive MIMO can **cause serious interference due to its broadcast tendency** to every direction at once. Thus, Beamforming is needed.


### 4.4 Beamforming
- Beam steering is a technology that **allows the massive MIMO base station antennas to direct the radio signal to the users and devices** rather than in all directions.
- The beam steering technology uses **advanced signal processing algorithms to determine the best path for the radio signal** to reach the user. This increases efficiency as it **reduces interference**.


## 5. 5G Operation Modes
- Currently, 5G is available in two deployment modes：
- Non-Standalone
- Standalone (True 5G network)


### 5.1 Non-Standalone (NSA)
In a NSA scenario, the 5G network will **rely on some previous generation (4G LTE) infrastructure**.For mobile operators looking to deliver better data throughput quickly, or to handle urgent LTE congestion, NSA mode makes the **most sense** because it **allows them to leverage their existing 4G network assets** rather than deploying a completely new end-to-end 5G network. **NSA allows an operator to launch 5G quickly** for eMBB to gain thought and market leadership.

### 5.2 Standalone (SA)
In a SA scenario, the **5G NR** or the evolved **LTE** radio cells and the **core network are operated alone**. This means that 5G SA network is **independent** of the 4G network. The 5G NR or evolved LTE radio cells are used for **both control plane and user plane**.

### 5.3 5G Deployment option


**Using the 4G Core Network (EPC)**
- Option 1 (SA)：LTE connected to EPC
- Basicly this one is fully 4G connection.
- Option 3 (NSA)：LTE assisted NR
- Connected to EPC

**Using the 5G Core Network 5GC**
- Option 2 (SA)：NR connected to 5GC.
- Basicly this one is fully 5G connection
- Option 5 (SA)：LTE connected to 5GC
- 4G basestation using the 5GC
- Option 4 (NSA)：NR assisted LTE connected to 5GC
- 4G basestation and 5G basestation (master) are co-existed but using 5GC
- Option 7 (NSA)：LTE assisted NR connected to 5GC
- 4G basestation (master) and 5G basestation are co-existed but using 5GC

**There are several migration paths that the operators could be used as their 5G roll out strategy：**


## 6. 5G Core

- 5G Core will be **Service Based Architecture (SBA)**, the SBA consist of SBI (Service Based INterface) and NF (Network Functions/ SBA APIs).


### 6.1 Compare with EPC


## 7. 5G Challenge (Focus on COST)

The 5G promise to support a wide range of services/applications/capabilities makes the **5G radio network more complex and expensive** — traditionally accounting for **70 to 80 percent of network costs**. We will use the concept of total cost of ownership (TCO) to evaluate the cost in this note.

TCO is a financial estimate intended to help buyers and owners determine the direct and indirect costs of a product or system, so it subsumes both CAPEX and OPEX but pays less regard to the vagaries of short-term CAPEX expensing.

### 7.1 5G-era Cost Accelerators (Factor of cost up)

**(1) RAN infrastructure**
- It is the **biggest cost ticket** for mobile operators, typically accounting for **45-50% of network TCO**.
- RAN infrastructure includes **passive infrastructure** and **active infrastructure**.
- Passive infrastructures are towers and cabinet. Because of deployment strategy such as densification using small cells, more dense the RAN infrasturcture, the operators must invest more on the passive infrastructure.
- Active infrastructure are radio antennas, baseband processing, related power and cooling equipment.

**(2) Massive MIMO and RAN densification**
- Delivering 5G coverage, capacity and a step increase in network performance (i.e. throughput and latency) to enhance existing services, require **5G RAN upgrades** that will lead to an **increase overall network TCO**, such upgrades will typically go along two avenues.
- Includes 5G upgrades of existing macrocells, and 5G-era Massive MIMO (mMIMO) upgrades.
- From 4x4 MIMO 4G RAN to 16 times larger (64 x 64 mMIMO)
- Network densification with additional small and macrocells, or macrocells alone.

**(3) Energy**
- More power/energy required to run denser, and higher capacity RAN.
- Energy is a major network cost item, the 4G network requires the cost of 20-25% of its TCO, 5G requires even more energy-**140% or more energy** on its network TCO.
- Three factors will drive a significant increase in 5G-era power consumption:
- M-MIMO：
Huawei estimates that M-MIMO alone can potentially increase energy consumption from 5-7 kW per 4G site per month to over 20kW per 5G-era site.
- Mobile data traffic growth：
Mobile data traffic growth of up to 50% adds to power consumption.
- More sites：
5G-era network densification with new macro and small cell sites in urban areas will add to the increase in total energy consumption.

**(4) Backhaul**

Backhaul transport networks already account for 10-15% of 4G-era network TCO, 5G-era traffic growth and RAN upgrades will demand high capacity, low latency backhaul upgrades that can increase backhaul costs by **up to 55%** in some deployment scenarios.

- Fibre is the best technology to deliver on 5G-era backhaul requirements for its throughput and latency performance, but also the costliest.
Mobile operators that already own fibre networks will, therefore, have a significant cost advantage against those that have to lease or build it themselves.
- It will require backhaul links upgrade to 10Gbps or 25 Gbps or even 100 Gbps.

### 7.2 What Technique can reduce 5G cost ?

- In this note, we will call the Technique of cost down 5G-era Cost Optimisers.

**(1) NVF (Network Virtualisation Function)**

NVF will be a major 5G-era cost optimiser that can deliver **savings of up to 25%** of network TCO, there are several strands of NVF with separate cost considerations and impact:

- RAN virtualisation with **C-RAN (Centralised or cloud-RAN)**：
- C-RAN provides infrastructure savings by stripping the cell site RAN equipment to basic radio and antenna functions (i.e. as an RRU) while centralising the baseband processing function of multiple RRUs at aggregation points as BBUs.
- C-RAN needs a very high capacity and low latency fronthaul which could be achieved by P2P fibre.
- Network Virtualization also usefull for new revenue generating services using network slicing or special API for better B2C services.

- Core virtualisation：
- Through decoupling the function into **VNFS**, it can run on VM over commercial-off-the-shelf (COTS) hardware.
- The control is **centralised**, which provides better network agility, as well as lower cost.

**(2) Automation and AI**

- Automation and artificial intelligence (AI) could deliver up to **25%** network TCO savings.
- Automation typically refers to rules-based, programmable, zero-touch execution of a (network) process.
- AI includes a range of techniques, of which machine learning (ML) is vital, that use self-learning algorithms to adapt and execute in specific network operating situations dynamically.

**(3) Network sharing**
- Network sharing will remain one of the **most significant cost mitigators** in the 5G-era.
Delivers TCO savings up to **40%** in instances where operators share spectrum, active and passive infrastructure across the site, radio, transport and core network domains.
- It ranges to Macro-level (i.e. Whole Market) and Micro-level(small cells in lamp posts, transport corridors,stadia) SNH(single neutral hosts).

**(4) Cloud and Open Source**
- Cloud and open source will be **modest cost optimisers** delivering savings up to **5%** of TCO.
- Even more critical will be the greater flexibility and agility that the two will yield for 5G operators in managing their cloud-native, virtualised 5G-era technology estate.
- Currently some operators trying deploy Opensource infrastructure, for example, AT&T deals with the use of Kubernetes and OpenStack as the container orchestration and clout infrastructure platform, as the foundations for its 5G rollout.

### 7.3 Three 5G deployment strategies


**(1) Strategy one：Full scale 5G deployment**

A full-scale 5G rollout that seeks to **rapidly cover 80% of the population** with a high-capacity 5G network would be, unsurprisingly, costly for an operator. This scenario can lead to a 5G-era overall network TCO Delta of up to 71%.


**(2) Strategy two：Enterprise focused 5G deployment**

A fast-paced, Enterprise focused 5G deployment indicates a slightly less daunting, albeit still substantial 5G-era TCO Delta of up to 46%, which can be optimised down to 24%.


**(3) Strategy three：Capacity-focused 5G deployment**

A capacity backfilling 5G rollout is **currently the most common operator approach**. The 5G cost accelerators in this scenario push the total 5G Delta by up to 25%, which can be reduced to 11% with keen cost optimisation. In effect, this scenario implies gradually rolling out a 5G network within the existing flat to low single-digit financial envelopes that most operators operate within.