LTE to 5G - Technical Discussion

[Signalian]

Hi, I am opening this topic to look into the technical aspects of LTE and 5G network. I will primarily look into the radio (RF) side of network however the discussion is not limited to certain technical aspect. 5G is also known as NR (New Radio) in technical terms.

Some key enabling technologies that are available within 5G radio services are as follows:

Millimeter wave Communications

Cellular networks usually use frequencies from 300 MHz to 3 GHz. Due to a higher wavelength, signals can be transmitted to several kilometers without significant loss. The penetration loss (buildings or other clutter) also is less and it is suitable for better indoor coverage in a sub-mmWave band. However, with the higher data demands, relying only on the spectrum below, 3GHz is not feasible as some data services require up to 10Gbps. 5G, with its potential to provide higher capacity, is exploring the opportunity to use the spectrum above 3GHz, mainly the mmWave range (30 GHz to 300 Ghz).

Later I will discuss the frequency spectrum of 2G, 3G, 4G LTE and 5G NR in depth as there are many frequency bands being utilized already. The advantage of the higher frequency bands is that they are much wider and they will be able to allow much higher signal bandwidths and hence support much higher data throughput rates. The disadvantage in some aspects is that they will have a much shorter range, but this is also an advantage because it will also allow much greater frequency re-use.

Massive Multiple Input – Multiple Output (mMIMO) or Massive MIMO

Massive MIMO is a key component in 5G new radio deployment. Each base station is equipped with multiple numbers of antennas transmitting concurrently using the same time-frequency resources. 5G is using the higher frequency bands with a shorter wavelength. As the wavelength reduces, the received signal power also reduces significantly. The transmitter and receiver antenna gain should be increased to overcome
this issue. Increasing the number of transmitters and receiver antennas is the practical solution to increase the gain. So mMIMO is playing a major role in 5G to improve received signal power.

I will describe small cells later. Macro cell is your usual default cell tower site.


MIMO can be single user SU-MIMO or multiple user MU-MIMO. In SU-MIMO, all the streams of antenna arrays are focused to single user. In MU-MIMO, different streams are focused to different users.

MIMO builds on the fact that a radio signal between transmitter and receiver is filtered by its environment, with reflections from buildings and other obstacles resulting in multiple signal paths.

The various reflected signals will arrive at the receiving antenna with differing:
1. time delays,
2. levels of attenuation (Signal loss) and
3. direction of travel.

When multiple receive antennas are deployed, each antenna receives a slightly different version of the signal, which can be combined mathematically to improve the quality of the transmitted signal.
This technique is known as spatial diversity since the receiver antennas are spatially separated from each other. Spatial diversity is also achieved by transmitting the radio signal over multiple antennas, with each antenna, in some cases, sending modified versions of the signal.

Whilst spatial diversity increases the reliability of the radio link, spatial multiplexing increases the capacity of the radio link by using the multiple transition paths as additional channels for carrying data. Spatial multiplexing allows multiple, unique, streams of data to be sent between the transmitter and receiver, significantly increasing throughput and also enabling multiple network users to be supported by a single transmitter, hence the term MU-MIMO.

Increased Network Capacity – Network Capacity is defined as the total data volume that can be served to a user and the maximum number of users that can be served with certain level of expected service. Massive MIMO contributes to increased capacity first by enabling 5G NR deployment in the higher frequency range in Sub-6 GHz (e.g., 3.5 GHz); and second by employing MU-MIMO where multiple users are served with the same time and frequency resources.

Improved Coverage – With massive MIMO, users enjoy a more uniform experience across the network, even at the cell’s edge – so users can expect high data rate service almost everywhere.

 

[Signalian]

3D Beamforming (Beamsteering)

Beamforming is a spatial signal processing technique with antenna array for directional signal transmission and reception by intentionally controlling the phase and relative amplitude on the same signal at each antenna. Contemporary multi-antenna base stations for cellular communications are equipped with 2-8 antennas which are deployed horizontally and are capable of steering beams in 2D. If we instead deploy multiple uniform liner arrays on top of each other, it is possible to control both the azimuth and elevation angle of a beam. This is called 3D beamforming.

With a massive number of antennas, beamforming creates beams both vertically and horizontally towards the user. The major advantages of 3D beamforming is increased data rate and capacity, less intercell and inter-sector interference, higher energy efficiency, improved coverage and increased spectral efficiency.

In simple words:
Beamforming enables the beam from the base station to be directed towards the mobile.

In this way the optimum signal can be transmitted to the mobile and received from it, whilst also cutting interference to other mobiles.

By adjusting the phase and amplitude of the transmitted signals, constructive addition of the corresponding signals at the UE (user end/mobile) receiver can be achieved, which increases the received signal strength and thus the end-user throughput. Similarly, when receiving, beamforming is the ability to collect the signal energy from a specific transmitter.

Beam forming for different clutters.

One of the benefits to beamforming is that it can deliver a high-quality signal to your receiver, overall improving wireless communication. Because it is a laser-focused technique, another benefit is that it can help reduce interference for other people trying to pick up a signal.

Beamforming also has limitations. Because beamforming is a complex technique that requires time, power resources and specific calculations, there’s always the risk of negating its benefits and advantages. Despite this issue, beamforming has improved over the years to be a more affordable technique that consumers can leverage.

Since 5G uses radio frequencies (30 GHz-300 GHz) to communicate with devices, there is a higher chance of signal interference or difficulty passing through physical objects. This problem can be resolved using strategies like using tons of antennas at a single 5G base station. But beamforming has the ability to solve this issue as well.

The move to higher frequencies allows for much smaller antennas and the possibility of programmable high directivity levels. On frequencies above 24 GHz where antennas are smaller, there is the possibility of having high performance beamsteering antennas that are able to accurately direct the power to the mobile, and also provide receiver gain in this direction.

 

[Signalian]

5G Network Slicing​

Network slicing is a network configuration that allows multiple networks (virtualized and independent ) to be created on top of a common physical infrastructure. This configuration has become an essential component of the overall 5G architectural landscape. Each “slice” or portion of the network can be allocated based on the specific needs of the application, use case or customer.

5G networks, in tandem with network slicing, enables users to enjoy requirement specific tailored connectivity and data processing that adhere to a Service Level Agreement (SLA) that the mobile operators have agreed with. Customisable network capabilities include data speed, quality, latency, reliability, security, and services.

A single network can be divided to cover diverse use cases based on customer demand and segmentation. Operators can then allocate resources to each slice, utilizing the necessary speed, throughput and latency to cover the breadth of network slicing in 5G. It can allow critical public entities, such as first responders and medical emergency teams, to be prioritized with respect to coverage, capacity and connectivity.

A 5G network slice can be dedicated to one enterprise customer, or shared by multiple tenants. For example, a slice may consist of dedicated radio, transport and core resources including a dedicated user plane function at the edge. Another slice shares radio & transport resources between tenants, but provides dedicated core network functions per tenant.

5G Network Slicing

• Create, modify, and delete a network slice.
• Define and update the set of services and capabilities supported in a network slice.
• Configure the information which associates a UE (mobile) to a network slice.
• Configure the information which associates a service to a network slice.
• Assign a UE to a network slice, to move a UE from one network slice to another, and to remove a UE from a network slice based on subscription, UE capabilities, operator's policies and services provided by the network slice.
• Support a mechanism for the VPLMN to assign a UE to a network slice with the needed services and authorized by the HPLMN, or to a default network slice.
• Enable a UE to be simultaneously assigned to and access services from more than one network slice of one operator.
• Traffic and services in one network slice shall have no impact on traffic and services in other network slices in the same network.
• Creation, modification, and deletion of a network slice shall have no or minimal impact on traffic and services in other network slices in the same network.
• Support the adaptation of capacity, i.e., elasticity of capacity of a network slice.
• Enable the network operator to define a minimum available capacity for a network slice. Elasticity of capacity in other network slices on the same network shall have no impact on the availability of the minimum capacity for that network slice.
• Enable the network operator to define a maximum capacity for a network slice.
• Enable the network operator to define a priority order between different networks slices in case multiple network slices compete for resources on the same network.
• Supports add and remove network functions to the network such that they can be used in a network slice.
• Support differentiate policy, functionality and performance provided in different network slices
• Support providing connectivity to home and roaming users in the same network slice.

 

[Signalian]

5G Non-Standalone (NSA) vs. 5G Standalone (SA)

The first phase of 5G deployment is covered in Non-Standalone (NSA) mode, where the 5G coexists and interworks with 4G. NSA deployment reduces the time and cost for deployment and ensures adequate coverage and mobility. From the network verification perspective, the performance of the 5G devices from accessibility, retainability, and mobility perspective will be dependent on the performance of the underlying LTE network.

Non-Standalone 5G​

The initial rollouts of 5G networks provide customers with higher data transfer speeds by pairing a 5G Radio Access Network (RAN) with the LTE Evolved Packet Core (EPC). Because the 5G RAN remains reliant on the 4G core network to manage control and signaling information and the 4G RAN continues to operate, this is called a Non-Standalone Architecture.

By leveraging the existing infrastructure of a 4G network, carriers are able to provide faster and more reliable Enhanced Mobile Broadband (eMBB) without completely reworking their core network technology and pushing customers to new devices. Non-Standalone 5G provides a transitionary platform for carriers and customers alike.

Non-Standalone 5G is

1. Quick to market
2. Add capacity with the new spectrum to enhance eMBB
3. Leverage on the existing infrastructure of 4G to get extended coverage for 5G and continuous mobility
4. Use of existing Evolved Core to be upgraded to accommodate 5G
5. An alternative to fiber, enable service over wireless to require higher throughput demand in a range of 100 Mbps

Standalone 5G​

Standalone 5G does not depend on an LTE EPC to operate. Rather, it pairs 5G radios with a cloud-native 5G core network. The 5G core itself is designed as a Service Based Architecture (SBA) which virtualizes network functions altogether, providing the full range of 5G features enterprise needs for factory automation, autonomous vehicle operation, and 5G use cases requiring ultra-low latency and much higher capacity will only be feasible with the SA 5G NR and the 3GPP core network architecture for 5G Core (5GC).

5G standalone enables the super-fast response times and faster access to higher data rates, that are required by Cloud gaiming, immersive media, and vehicles or robots control. Compared to 4G/5G Dual Connectivity, Carrier Aggregation boosts network capacity by 27 percent and brings coverage to 25 percent more people that use the mid-band for the downlink.

Standalone 5G has

1. Simplified RAN architecture
2. Expected low price handset with SA option
3. New Cloud-Native 5G Core to take full advantage of virtualization
4. Use cases to build based on Virtualizations and Slicing
5. Ultra-Low Latency advantage and also more enhancement by doing Edge-Core computing
6. Facilitate a broader range of use cases

 

[Signalian]

PRIVATE LTE / PRIVATE 5G

Private LTE networks are privately-owned cellular networks made of multiple components, including radio hardware (both indoors and outdoors), mobile core software, SIM cards and a network orchestration software that can be configured to support an enterprise’s specific requirements.

Private LTE networks use the same technology as commercial public LTE, but without having to pay one of the main mobile operators (Vodafone, AT&T, Telenor) to use their network. Just like the public LTE network used today with smartphone, similarly mobile and cellular devices can connect to the private LTE network.

This is similar to the public cellular networks most of us use every day via our smartphones, but in this case, the network is owned and operated by a private institution like a business, hospital, university, factory, or other enterprise and bound geographically to its property.

Case Example:
A large hospital.

Many hospitals are using a traditional Wi-Fi network to try to provide mobile connectivity to their entire building and campus, but the network suffers from the limitations of Wi-Fi, including reliability, security, capacity, and coverage issues.

One alternative is to use a public cellular network operated by Mobile operator like Vodafone etc. But public cellular networks lack the performance and security most hospitals require and can be very expensive. Also, the hospital’s IT department has very little control over the public network, which makes it difficult to tailor this network to the hospital’s specific needs. With private LTE, the hospital doesn’t face the reliability, speed and coverage problems of traditional Wi-Fi. And with the network being private, the hospital doesn’t face the same security threats or need to pay a mobile operator for congested mobile networks that weren’t designed for the hospital’s custom needs.

The basic requirements for a private wireless network are:

• A radio network (RAN)
• A core network
• A backhaul network
• Access to licensed, shared or unlicensed radio spectrum.

Radio access points provide coverage of outdoor and indoor spaces, similar to Wi-Fi, but fewer are needed. Unlike Wi-Fi, there is a core network, which is the key to enabling mobility, ensuring security and maintaining quality-of-service parameters. Depending on the size of site, it can even run on a small desktop-sized edge server deployed in a server room.
The backhaul network is no different than a system used to connect Wi-Fi access points, whether cabled Ethernet, passive optical LAN and/or microwave depending on the application and the distances served.

In terms of RF (RAN- Radio Access Network), many utilities use 900 MHz currently for voice and narrowband data for land mobile radio communications, 900 MHz broadband for critical wide area, long-range data communications, and CBRS (Citizens Broadband Radio Service 3550-3700 MHz) for ultra-fast coverage of smaller areas like substations, storage yards and office spaces. With new spectrum becoming available for utilities, the opportunity for more robust data communication can now include video, sensors, analytics and more. 1800 MHz spectrum can also be used in Private LTE. Devices within a private LTE network depend on localized base stations or LTE Small Cells (eNodeB) to ensure connectivity.

RAN Parameters
The parameters of LTE which greatly come into play for private LTE Vs Wi-Fi are
1. HARQ (Hybrid automatic repeat request which allows recovering from residual errors by link adaptation.) with channel information,
2. The modulation schemes (8 QPSK, 16 QAM and 64 QAM, 256 QAM) are more granular, as well as coding schemes and
3. Adaptive schedulers (Dynamic Scheduling, Persistent Scheduling, Semi-Persistent Scheduling).

One LTE small cell will cover approx. same area as 5-7 Wi-Fi access points at more or less equivalent power output. If CBRS 3.5 GHz spectrum is used or Category-B small cells are used then range can be significantly greater still. 30 Wi-Fi points can be replaced with 4 and later more LTE BTs eNodeB.

One of the primary components of a private LTE network is something called the Evolved Packet Core or EPC. The EPC is the “brains'' of the private LTE network that can be located on on-premise, or hosted by a third-party as a managed service. EPC operations consist of different components that all work together to help direct, authenticate, and prioritize network traffic. These smaller sub components include:

• Mobility Management Entity (MME)
• Serving Gateway (SGW)
• Packet Data Network Gateway (PGW)
• Home Subscriber Server (HSS)
• Access Network Discovery and Selection Function (ANDSF)
• Evolved Packet Data Gateway (ePDG)

The EPC follows standards outlined by the Third Generation Partnership Project (3GPP). The way EPC functions gives the LTE network a flat architecture, meaning it doesn’t have to rely on protocol conversions to function. A flat architecture gives private LTE increased data handling efficiency as well additional flexibility across different devices and networks.

Different types of gateways manage the private LTE traffic by connecting it to the cloud through edge devices, or keeping the traffic local if needed. The Packet Gateway (PGW) is responsible for maintaining a secure link between the local private LTE network and the rest of the internet. The PGW can filter and establish connections to other devices outside of the network, and acts as a bridge of communication between 3GPP and non-3GPP technology.

Benefits of Private LTE
Here are just a few ways private LTE benefits enterprise organizations.

LTE itself, but private. One of the best parts of private LTE is that there is no need to go through a mobile operator. This means the enterprise (hospital, university, prison, mine etc) where its deployed is in control of your data usage, where network coverage is present, and which devices have priority over others. This also lowers bandwidth costs.

Customization. Ability to design, architect, and optimize P-LTE network to enterprise’s specific needs. This is especially important if enterprise requires performance they could never get through someone else’s public commercial LTE network. Customization could include HIPAA (Health Insurance Portability and Accountability Act) compliant architecture, device specific prioritization in an office, application level service level agreements (SLAs) for throughput, latency, packet error rate metrics, or a custom cell tower configuration for remote locations.

Security. Private LTE keeps all sensitive information and confidential data within defined network—rather than going through someone else’s public commercial network—and can be made more secure than traditional Wi-Fi with device specific policies, authorization and always-on centralized encryption. This is mostly in part due to the use of physical and embedded SIM technology on client devices. Unlike Wi-Fi, devices cannot simply put in a password and join a network - they are only admitted after certificate based authentication with a previously assigned SIM identity.

Reliability. LTE can be optimized for low and predictable latency - and on a per application basis if Network Slicing technology is in action. Wi-Fi of course tends to be less predictable in terms of specific network metrics, especially in a spectrum that is often congested with noise and interference. And public commercial LTE isn’t tailor-made to a building's and personal needs, so it can’t be optimized to be as performant as private LTE.

Coverage. LTE networks can be optimized to have up to 10x the coverage outdoors when compared Wi-Fi and up to 4x when indoors. For years Wi-Fi has relied on wireless bridges and signal repeaters to compensate in similar environments and these band-aids tend to create more points of failure and increased operational cost.

 

[sur]

Any word on possible health impact [or lack of] of such a high frequency waves in even higher intensities [if I understood correctly shorter range and loss compensated by more number of waves per unit area , I believe called flux or intensity? in F.Sc physics]



Not that I believe covid was caused by 5G but is there any other established or probable health impact, resulting from antennas or from 5G frequency devices held closer to head or gonads when in pocket, etc.

 

[Signalian]

Any word on possible health impact [or lack of] of such a high frequency waves in even higher intensities [if I understood correctly shorter range and loss compensated by more number of waves per unit area , I believe called flux or intensity? in F.Sc physics]



Not that I believe covid was caused by 5G but is there any other established or probable health impact, resulting from antennas or from 5G frequency devices held closer to head or gonads when in pocket, etc.

Since the release of 5G, many false claims about its health appeared on social media. Examples of these myths include:
1. COVID-19 vaccines contain 5G microchips
2. 5G release is used to cover up the COVID-19 pandemic
3. 5G causes headaches, migraines, and dizziness
There is no proof behind these claims.

There’s also a myth that 5G mobile networks are associated with the new coronavirus SARS-CoV-2, which causes the condition COVID-19. This is false. According to rumors, 5G is said to directly spread the virus. But viruses spread through respiratory droplets, not wireless networks. Some rumors claim that 5G suppresses your immune system, increasing your risk of contracting SARS-CoV-2, which causes COVID-19. But this is also false. There is no proof that EMFs or 5G affects your risk of developing viral infections.

5G does generate radiation, but at very safe levels, and none of it is radioactive radiation. 5G base stations and phones, and the frequency ranges within which 5G operates, are very likely to be operating well within safe parameters in 2022 and throughout 5G’s lifetime, which may extend to two decades. Radiation within these parameters does not significantly raise the risk of cancer. It also does not weaken the immune system, and thus has not contributed to the spread of COVID-19.

5G also incorporates a technique known as beamforming, an approach that involves directing a narrow beam of radio waves to the user device (such as a smartphone). This method is equivalent to directing a narrow beam of light from a pocket flashlight at a target, focusing the radio waves on the device. This method not only enables higher connection speeds, but also leads to lower radio wave exposure than prior network generations, which would often spread radio waves across a wide arc, similar to a car’s headlight.

The power generated by mobile network base stations is similarly low. A base station’s transmissions range in power from a quarter of a watt for a small cell (which would often be indoors and cover a small range) to 200 watts for a minority of 5G base stations. More typically, an outdoor base station with the greatest range would have a power output of between 10 and 100 watts. The output of indoor base stations, which usually have a range of hundreds of meters or less, is much lower.

As with a phone, a base station’s power level declines with distance from its transmitter. An individual 100 meters away from a 5G macro-cell antenna located at 30 meters’ height would absorb less than one microwatt (one-thousandth of a watt) of power. When one is directly next to a base station supporting any generation of mobile standard (not just 5G), exposure limits may be exceeded. But these areas are inaccessible to the public, sometimes because of their height (20 meters or higher for larger sites), their location (often at the top of buildings), or their design (because the units are enclosed). In the case of indoor base stations, excessive exposure would only happen within a few centimeters of the transmitter.

5G has been designed to use less power than previous generations to reduce operational costs; as a result, it emits less power as well. This is accomplished via the new, advanced radio and core architecture used in the 5G standard, with 5G networks assisting 5G devices in minimizing power transmit levels. 5G base stations also can be put into sleep mode when there are no active users (for example, at night). This capability is not available with 4G networks, which transmit control signals even when there are no users in range.

Tests of 5G sites in 2020 by regulators such as Ofcom in the United Kingdom have found that their EMF levels are well within International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. ICNIRP is an independent scientific commission based in Germany that works with the World Health Organization (WHO), the International Labour Organization (ILO), and the European Commission.

 

[Signalian]

Distributed Antenna Systems (DAS)

The in-building solution for Mobile communication is now commonly known as DAS (Distributed Antenna Systems). In-Building Distributed Antenna Systems (DAS) have become a critical part of both carrier cellular networks and enterprise infrastructure. But as the technology has evolved over the last 20 years it has become increasingly complex.

Where is DAS needed ? Shopping Malls, Airports, hotels etc

How a DAS Works​

A DAS is a network of antennas that sends and receives cellular signals on a carrier’s licensed frequencies, thereby improving voice and data connectivity for end-users.

In its most simplified form, a DAS has two basic components:

1 - A signal source
A Distributed Antenna System, as the name implies, “distributes” signal. But it generally doesn’t generate the cellular signal itself. A DAS needs to be fed signal from somewhere. Whether it's 4G LTE or 5G, there are four typical signal sources: off-air (via an antenna on the roof), an on-site BTS (Base Transceiver Station), and finally the newest approach: small cells. The antenna which gives the signal source from LTE network is called repeater.

2 - Distribution system
Once received, the cellular signal must be distributed throughout the building. There are four main types of distribution systems: active (using fiber optic or ethernet cable), passive, hybrid, and digital.
A distributed antenna system’s performance depends on the type of technology it uses. To understand what we mean by “performance,” we first need to understand the two main performance metrics: coverage and capacity.

Signal Sources​

The signal sources for a DAS system are one of the single most important factors in determining both the coverage area and capacity. No matter how well the distribution system performs, a DAS is always limited by the performance of the signal supplying the network. The signal source also determines what kind of signal the DAS distributes. For example, a 5G signal source is a requirement for a 5G DAS. The three main signal sources are off-air, BTS/NodeB/eNodeB, and small cell.

1. Off-Air​

A DAS that uses an off-air signal (sometimes called a repeater) utilizes a donor antenna on the roof to receive and transmit signals from a cell carrier. Off-air signals are the most common signal sources for a DAS. If the signal at the donor antenna is very weak or the nearest tower is quite congested, using an off-air signal isn't typically feasible. But if the donor signal is strong and clear, then an off-air signal is often the easiest and most cost-effective signal source.

A DAS that uses an off-air signal source does not add any extra capacity to the carrier’s network and is primarily used to extend coverage at the edges of the network. These deployments are often the lowest cost option and are most suitable when the primary reason for deploying a DAS is to extend coverage inside a building.

Almost all DAS systems are can use off-air signal, but Wilson Electronics, SureCall, and Cel-Fi are most often associated with this type of deployment. Off-air DAS deployments have seen a resurgence with the roll-out of 5G, particularly on mmWave bands.

Choosing an integrator with a strong RF (radio frequency) experience is critical when implementing an off-air DAS system. The performance of the DAS will depend strongly on proper evaluation and optimization of the donor signal.

2. BTS, NodeB, eNodeB, gNodeB​

Base Transceiver Station (BTS), NodeB, eNodeB, gNodeB refer to the technology used inside cell phone towers to generate a cellular signal. For simplicity, these technologies are often referred to simply as a BTS signal source.

The connection between a cell carrier's BTS and the core network typically requires a dedicated fiber connection that is usually installed by the carrier themselves. A distributed antenna system in a large stadium or airport may even connect to multiple BTSes—one for each carrier—to handle the load of tens of thousands of users calling, texting, and using data simultaneously.

DAS systems that use BTS signal sources typically take longer to deploy and are more expensive; each carrier must run their own fiber and the BTSes themselves are typically at least $50k+ each.

Nokia and Ericsson are the two most common vendors of BTS and eNodeBs for DAS deployments.

3. Enterprise Small Cells (Femtocells, Picocells and MetroCell)​

Small cells are the latest technology used by carriers to provide cellular service inside buildings. There are several variations of small cells, including femtocells, picocells, nanocells, and metrocells. These are all basically the same technology—they create a secure tunnel back to the carrier’s network over a normal Internet connection and generate a high-quality wireless signal.

The typical coverage area of a small cell is only about 5,000 to 15,000 square feet, and they are relatively expensive. While covering larger venues with dozens of small cells isn’t cost-effective, the coverage area of a small cell can be greatly expanded by using them as a signal source for a distributed antenna system. One limitation of small cell technology is that they require a reliable backhaul Internet connection to connect. Each enterprise-grade small cell typically supports around 200 users. We’ve installed many DAS deployments using small cells as a signal source, and the results are typically excellent. We expect this will be the fastest-growing new technology in the DAS space.

Nokia, Samsung, Casa Networks, Spidercloud, and Airspan are the most popular vendors of enterprise-grade small cells.

Signal Distribution Technologies​

Whichever signal source a system uses, a DAS needs to amplify, distribute and rebroadcast it through the building. There are four main types of signal distribution technology: active, passive, hybrid and digital.

1. Passive DAS​

A passive DAS uses passive RF components such as coaxial cable, splitters, taps, and couplers to distribute signal inside a building. The farther the antenna is from the signal source and any amplifiers, the more attenuation (loss) there will be in the power broadcast from that antenna. Designing a passive DAS correctly requires calculating precise link budgets to make sure the outputted power at each antenna is equal.
Wilson Electronics and SureCall are the two vendors most commonly associated with passive DAS systems, but passive DAS equipment is also offered by more traditional vendors such as Commscope, SOLiD, and ADRF.

Passive DAS deployments are typically simpler than other types of distributed antenna systems, which our customers appreciate. However, performance limitations often mean that we recommend active or hybrid DAS systems for medium-sized and larger buildings.

2. Active DAS​

An Active DAS converts the radio frequency transmissions from the signal source signal so they can be distributed via an optical or ethernet cable. A "master unit" combines the signals from multiple carriers and performs this conversion. Some Active DAS systems also "digitize" this signal which adds cost but improves performance (see below). Once converted, an Active DAS transmits the digital signal over fiber optic ("Fiber DAS") or ethernet cables to remote radio units (RRUs) that convert the signal back to an RF signal. These RRUs are also sometimes called "nodes" or even "active antennas" depending on the vendor and the architecture of the system.

Unlike their Passive DAS counterparts, Active DAS deployments minimize the use of coaxial cable used to distribute signal. In some cases there is no coaxial at all; this is called a "fiber to the antenna" or "fiber to the node" system.

Corning, Commscope, SOLiD, Comba Telecom, and ADRF all offer variants of active and fiber DAS systems.

3. Hybrid DAS​

A hybrid DAS combines the characteristics of passive and active systems. The RRUs are separate from the antennas, allowing the system to use both fiber optic cable and coaxial cable to distribute signal throughout a building. Because this configuration requires fewer RRUs, a hybrid DAS normally costs less than an active DAS.

A typical hybrid DAS configuration includes an RRU on each floor that converts from the digital signal to analog RF. The analog RF signal is then connected to multiple antennas on that floor with coaxial cable.

The same active DAS vendors (Corning, Commscope, SOLiD, Comba Telecom, and ADRF) all offer hybrid DAS options, typically at a lower cost than their "fiber to the antenna/node" solutions.

Cel-Fi also markets their QUATRA product line as a hybrid system due to its cost savings, even though the system is more similar to an Active DAS in some ways.

4. Digital DAS​

A Digital DAS converts each carrier's signal to zeros and ones before combining them and transmitting over fiber optic or ethernet cable. This conversion and combination process is computationally expensive, which makes digital DAS systems considerably more expensive than their analog counterparts.

One of the biggest benefits of deploying a Digital DAS is that they are much less susceptible to interference, and thus more performant. A second benefit is that Digital DAS platforms allow the capacity of the signal sources to be directed to different areas of a venue. This is particularly important when the capacity of a building shifts dynamically – think for example of a large cafeteria or event space on a school, university, or office space.

If both the signal source and Digital DAS platform support the "Common Public Radio Interface" (CPRI) specification, it's possible for a signal source's Baseband Unit (BBU) to communicate directly with the DAS master unit and through to the remote units without any conversion to an analog RF signal.

Corning, Commscope, ADRF, and SOLiD all offer Digital DAS platforms.

Reference: waveform.com

 

[jamahir]

Thanks. Bookmarked.

 

[Signalian]

TIMELINE for Cellular Networks (expected for 5.5 and 6G)

 

[SQ8]

View attachment 864319

TIMELINE for Cellular Networks (expected for 5.5 and 6G)

View attachment 864322

My interest was using the beam forming you get from the ESAs for 5G and onwards to charge devices.. specifically IoT ones. If you can solve that problem and pair it with really low power sensors for basic stuff such as overfill alarms or otherwise.. that is a big deal.

But think of sensors running at 5V or less and at decimal mA levels

But that was telecommunication’s engineering and Im so far from that now

 

[lastofthepatriots]

My interest was using the beam forming you get from the ESAs for 5G and onwards to charge devices.. specifically IoT ones. If you can solve that problem and pair it with really low power sensors for basic stuff such as overfill alarms or otherwise.. that is a big deal.

But think of sensors running at 5V or less and at decimal mA levels

But that was telecommunication’s engineering and Im so far from that now

How would the devices be charged?

 

[SQ8]

How would the devices be charged?

You can deliver power through 5G signals
https://www.popularmechanics.com/technology/infrastructure/a35407385/wireless-power-grid-5g/

The problem comes in power attenuation because either you need it pretty close to you to deliver sufficient power at current beam power and signal losses or you need really low power devices.

 

[unrequitted_love_suzy]

5G is nothing special , UW 5G is fiber distributed through FTTA scheme , Fiber to the antenna . without Fiber it's fake 5G and the speed is no more than 200-300 megabits per second.