4G LTE

What is 4G (fourth-generation wireless)?

- 4G is the short name for fourth-generation wireless, the stage of broadband mobile communications that supersedes 3G (third-generation wireless) and is the predecessor of 5G (fifth-generation wireless). - The 4G wireless cellular standard was defined by the International Telecommunication Union (ITU) and specifies the key characteristics of the standard, including transmission technology and data speeds. - 4G users get speeds of up to 100 Mbps, while 3G only promised a peak speed of 14 Mbps. - With 4G download speeds, wireless users can stream high-definition video and audio. - 4G also enables wireless broadband, which provides a way for users to get internet connectivity without the need for a fixed, wired connection from an internet service provider (ISP).

What are mobile hotspots?

- A mobile hotspot is an ad hoc wireless access point that is created by a dedicated hardware device or a smartphone feature that shares the phone's cellular data. Other nearby devices can then use the shared hotspot to connect to the internet. - A mobile hotspot is an ad hoc wireless access point that is created by a dedicated hardware device or a smartphone feature that shares the phone's cellular data. - Other nearby devices can then use the shared hotspot to connect to the internet. - Pocket routers access cellular signals and convert 3G and 4G signals to Wi-Fi and vice versa, creating mobile Wi-Fi networks that can be shared by multiple users within about 10 meters of the device - Many smartphones enable the creation of a mobile hotspot through tethering, accessing the phone's existing cellular data connection.

What is the difference between a transmitter and a transceiver?

- A transmitter is a separate electronic component that generates a radio frequency (RF) current or radio waves. These waves are used in communication systems to transfer data like audio, video, etc. - A transceiver, on the other hand, can both send and receive digital signals.

Other beamforming techniques include the following:

- Analog beamforming uses phase-shifters to send the same signal from multiple antennas. The signal is set to different phases, which creates an antenna pattern that points a specific direction. The signal phases of antenna signals are adjusted in an RF domain, which improves coverage - Digital beamforming has different signals for each antenna in a digital baseband. Digital receivers are placed at the radiating elements of each antenna. Different phases are applied to different frequency bands, enabling digital beamforming to be more flexible. A digital beamforming processor can then steer numerous independent beams in any direction. This method is useful for spatial multiplexing. - Hybrid beamforming is a combination of analog and digital beamforming. The hybrid approach uses analog beamforming along with digital precoding, which is used to support multistream transmission, to form the patterns transmitted from an antenna array. The process defines the number of analog beams while allowing for some frequency variations. 5G base stations can use hybrid beamforming. - Massive MIMO, or multiple input and multiple output, is an antenna technology for wireless networks where multiple antennas are used at both the transmitter and the receiver ends. Massive MIMO uses a common frequency that is then steered in multiple directions. It requires digital signal processors and an area with a lot of signal interference. The different signal arrival times form multiple time-division duplexing channels, providing path redundancy. Massive MIMO is used in wireless, Wi-Fi and 5G technology. - Beam steering changes the phase of input signals on each radiating antenna element. This method essentially tracks the receiving device, steering a signal to it. A common frequency is steered with a signal beam in the correct direction. Meanwhile, different signals can be sent to other

How does 4G work?

- At the most basic level, a 4G connection works via an antenna that transmits over radio frequencies, enabling mobile devices to connect to mobile networks. - The transmission and receiving capabilities of 4G are powered by MIMO (Multiple Input Multiple Output) and Orthogonal Frequency Division Multiplexing (OFDM) technologies. Both MIMO and OFDM enable more capacity and bandwidth in comparison to 3G. - OFDM provides more speed than the primary technologies that powered 3G, which include TDMA (Time Division Multiple Access) and CDMA (Code Division Multiple Access) technology. - With MIMO, 4G reduces network congestion in comparison to 3G, because more users can be supported.

MIMO and beamforming

- Beamforming is an RF management technique that maximizes the signal power at the receiver by focusing broadcast data to specific users instead of a large area. - With 5G, three-dimensional (3D) beamforming forms and directs vertical and horizontal beams at the user. - These can reach devices even if they're at the top of a high-rise, for example. - The beams prevent interference with other wireless signals and stay with users as they move throughout a given area.

What is Code Division Multiple Access (CDM)

- Code division multiplexing (CDM) is a multiplexing technique that uses spread spectrum communication. - In spread spectrum communications, a narrowband signal is spread over a larger band of frequency or across multiple channels via division. - It does not constrict bandwidth's digital signals or frequencies. - It is less susceptible to interference, thus providing better data communication capability and a more secure private line - When CDM is used to allow multiple signals from multiple users to share a common communication channel, the technology is called Code Division Multiple Access (CDMA). - Each group of users is given a shared code and individual conversations are encoded in a digital sequence. - Data is available on the shared channel, but only those users associated with a particular code can access the data.

Limitations of wireless broadband

- Data limits. Some services may come with data limits; however, users can normally choose a plan that offers different data rates. - Signal consistency. If there are mobile network issues, a user's connection could stop working. Signal strength also weakens when the signal passes through thick walls or roofs. Bad weather might also weaken internet speeds. - Security. Unauthorized access will narrow network bandwidth, slowing speeds.

Advantages of wireless broadband

- Download/upload speeds. Download speeds differ per region and country; however, the minimum speeds in the U.S. and the EU, respectively, are 25 and 24 Mbps. Currently, in the United States, mobile wireless broadband averages 79.2 Mbps for downloads and for 9.29 Mbps uploads, while the global averages are 37.98 Mbps download and 9.75 Mbps upload. - Range. The range of a wireless broadband signal is commonly about 31 miles from a nearby tower. - Symmetrical/asymmetrical data rates. Some service providers will offer the same upload speeds as download speeds, while others may offer higher download speeds.

How orthogonal frequency-division multiplexing works?

- In the traditional stream, each bit might be represented by a 1 nanosecond segment of the signal, with 0.25 ns spacing between bits, for example. - Using OFDM to split the signal across four component streams lets each bit be represented by 4 ns of the signal with 1 ns spacing between. -The overall data rate is the same, 4 bits every 5 ns, but the signal integrity is higher. - Imagine you were sending a letter to your grandmother. You could write your letter on a single piece of paper and mail it to her in an envelope. - This would be like using a single frequency (one piece of paper) to send your entire message. But, because your grandmother can't see well, you instead write the same message in larger letters (a slower data rate) on several pieces of paper (representing data streams on different channels) but put them all in the same envelope (using same overall frequency spectrum). - OFDM builds on simpler frequency-division multiplexing (FDM)

Current limitations of beamforming

- It sometimes requires more computing resources and power for beamforming calculations. - Digital and massive MIMO beamforming systems may be more complex, especially considering more antennas and other hardware used. - Its cost tends to be higher than traditional systems

Bandwidth alone is not the only benefit of moving to 5G. Other benefits of 5G include:

- Lower latency. 5G enables more responsive, faster connections. 5G latency is intended to be less than 1 millisecond, which is significantly faster than the 60 to 98 milliseconds that 4G enables. - Less congestion. 5G also offers less signal interference than 4G. Both 4G and 5G use OFDM technology, which splits signals into different channels. While 4G provides 20 MHz channels, 5G has channels in the 100 to 800 MHz range, enabling more capacity, less congestion and higher download speeds. - Power consumption. For mobile devices, 5G has the potential to consume less energy on consumer devices and smartphones than 4G, which could enable longer battery life for devices.

What is MIMO (multiple input, multiple output)?

- MIMO (multiple input, multiple output) is an antenna technology for wireless communications in which multiple antennas are used at both the source (transmitter) and the destination (receiver). - The antennas at each end of the communications circuit are combined to minimize errors, optimize data speed and improve the capacity of radio transmissions by enabling data to travel over many signal paths at the same time. - Creating multiple versions of the same signal provides more opportunities for the data to reach the receiving antenna without being affected by fading, which increases the signal-to-noise ratio and error rate. - By boosting the capacity of radio frequency (RF) systems, MIMO creates a more stable connection and less congestion.

MIMO and 5G massive systems:

- MIMO continues to upgrade and grow through its use in massive new applications, as the wireless industry works to accommodate more antennas, networks and devices. - One of the most prominent examples of this is the rollout of 5G technology. - These massive 5G MIMO systems use numerous small antennas to boost bandwidth to users -- not just transmission rates as with third-generation (3G) and 4G cellular technology -- and support more users per antenna. - Unlike 4G MIMO, which uses a frequency division duplex (FDD) system for supporting multiple devices, 5G massive MIMO uses a different setup called time division duplex (TDD). - This offers numerous advantages over FDD

LTE applications of MIMO:

- MIMO is one of the most common forms of wireless, and it played a key role in the deployment of LTE and the wireless broadband technology standard Worldwide Interoperability for Microwave Access (WiMAX>) - LTE uses MIMO and orthogonal frequency-division multiplexing (OFDM) to increase speeds up to 100 megabits per second (mbps) and beyond. - These rates are double what was offered in previous 802.11a Wi-Fi. LTE uses MIMO for transmit diversity, spatial multiplexing (to transmit spatially separated independent channels), and single-user and multiuser systems.

What are megabits per second (Mbps)?

- Megabits per second (Mbps) are units of measurement for network bandwidth and throughput. - They are used to show how fast a network or internet connection is. - Each Mbps represents the capacity to transfer 1 million bits each second, or roughly one small photo per second. - It may also be expressed as Mbit/s or Mb/s. - A bit is the smallest measure of binary data. Each bit is a single 0 or 1. A megabit is 1 million bits.

Benefits of beamforming

- More power is directed in the beam's specified direction. - Higher signal quality reaches the receiving device, which increases the coverage capacity of the cell tower or base station. - There are faster information transfers and fewer errors. - Signal interference between devices is avoided since signals are only broadcast where needed. - Analog beamforming is relatively simple to implement and has lower power requirements

The importance of MIMO for users:

- The 3rd Generation Partnership Project (3GPP) added MIMO with Release 8 of the Mobile Broadband Standard. - MIMO technology is used for Wi-Fi networks and cellular fourth-generation (4G) Long-Term Evolution (LTE) and fifth-generation (5G) technology in a wide range of markets, including law enforcement, broadcast TV production and government - MIMO is often used for high-bandwidth communications where it's important to not have interference from microwave or RF systems. - For example, it's frequently used by first responders who can't always rely on cell networks during a disaster or power outage or when a cell network is overloaded.

What is twisted pair?

- Twisted pair is the ordinary copper wire that connects home and business computers to the telephone company. - To reduce crosstalk or electromagnetic induction between pairs of wires, two insulated copper wires are twisted around each other. - Each connection on twisted pair requires both wires. - Since some telephones or desktop locations require multiple connections, twisted pair is sometimes installed in two or more pairs, all within a single cable. - For some business locations, twisted pair is enclosed in a shield that functions as a ground. - This is known as shielded twisted pair (STP). - Ordinary wire to the home is unshielded twisted pair (UTP).

What is wireless broadband? (WiBB):

- Wireless broadband (WiBB) is a high-speed internet and data service delivered through a wireless local area network (WLAN) or wireless wide area network (WWAN). - As with other wireless services, wireless broadband may be either fixed or mobile. - The term broadband generally refers to relatively high-speed internet access. It includes several high-speed transmission technologies such as cable modems, fiber, satellite and wireless. - Wireless broadband speeds are defined by the FCC to be at least 25 megabits per second (Mbps).

What are the differences among FDM, TDM and STDM?

1. In TDM (time-division multiplexing), the capacity of the outgoing channel is divided into multiple channels, with the data from each incoming channel placed in one outgoing logical channel. It divides time -- on the outgoing channel -- into fixed-length and definite intervals called frames. The medium's data transfer rate, meanwhile, is greater than that of the source. Also, all signals operate at the same frequency but at different times. This differentiates TDM from FDM, where different signals operate at different frequencies at the same time. TDM is easy to implement. However, the outgoing channel utilization can vary depending on the burstiness of the incoming data streams. If the incoming data is not bursty, TDM leads to high utilization, making it most suitable for constant bit rate traffic. 2. In STDM, the capacity allocated to each incoming channel varies with time and depends on its instantaneous data rate. This is why it can work when the capacity of the outgoing channel is only as large as the sum of the average data rates of the incoming channels -- it may even be smaller. STDM is best used for applications with bursty input data. Code-division multiplexing is another method for multiplexing different bit streams on a single link.

Benefits of moving to 5G

5G is the next evolution of mobile network technology. It offers the promise of increased bandwidth with peak speeds as high as 20 Gbps, which is dramatically more than the 100 Mbps specified by 4G.

What is a data plan (mobile data plan)

A data plan is an agreement between a mobile carrier and a customer that specifies how much mobile data the user can access, usually per month, for a specific fee Since the advent of the smartphone, most mobile service providers offer data plans at varying rates based on the amount of data transfer allowed before a data cap is imposed. Some data plans include voice, text messaging and data while others are broken into separate charges, one for phone and text and another for data Some mobile users opt to forgo data and make do with Wi-Fi for Internet access. However, a data plan enables access in areas outside of the range of available Wi-Fi networks. A phone's default setting might be, for example, to switch to mobile data automatically when the device moves out of Wi-Fi range or to use mobile data in conjunction with Wi-Fi for more bandwidth. A user's failure to switch the phone to Wi-Fi when it's available can also result in unexpectedly high mobile bills

What is a transceiver?

A transceiver is a combination transmitter/receiver in a single package. While the term typically applies to wireless communications devices, it can also be used for transmitter/receiver devices in cable or optical fiber systems. The main functionality of this electronic device is to transmit, as well as receive, different signals.

Frequency-division multiplexing applications:

A typical analog internet connection via a twisted-pair cable requires approximately 3 kHz bandwidth for accurate and reliable data transfer. Twisted-pair lines are common in households and small businesses. FDM enables single transmission mediums, such as copper cable or fiber optic cable, to be shared by multiple independent signals that are generated by multiple users. This is why FDM is a popular choice to multiplex calls in telephone networks.

Future of beamforming technology

Beamforming has the potential to become more common in Wi-Fi and 5G networks, and it may become a necessary technology to help communication networks meet future data rates and network capacities. In addition, as beamforming algorithms improve, beamforming will be able to select the best data paths.

What is beamforming?

Beamforming is a type of radio frequency (RF) management in which a wireless signal is directed toward a specific receiving device. Beamforming is applied to numerous technologies, including wireless communications, acoustics, radar and sonar. The RF management technique directs radio and sound waves for signal transmission or reception Rather than sending a signal from a broadcast antenna to be spread in all directions -- how a signal would traditionally be sent -- beamforming uses multiple antennas to send out and direct the same signal toward a single receiving device, such as a laptop, smartphone or tablet. The connection results in a faster, more reliable wireless data transfer.

How does beamforming work?

Beamforming works differently, depending on its type or implementation. However, by having multiple antennas in close proximity send out multiple signals at different times, a beamforming tower or router can adjust the signals it sends This adjustment determines the best path for the signal to take to reach the client device. In a sense, beamforming shapes the RF beam as it traverses a physical space.

Before MIMO _____

Before MIMO, there were other types of advanced antenna technology with different configurations -- most commonly, multiple input, single output (MISO) and single input, multiple output (SIMO). MIMO builds on these technologies

How did 4G technology evolve from 3G tech?

Both MIMO and OFDM enable more capacity and bandwidth in comparison to 3G. OFDM provides more speed than the primary technologies that powered 3G, which include TDMA (Time Division Multiple Access) and CDMA (Code Division Multiple Access) technology With MIMO, 4G reduces network congestion in comparison to 3G, because more users can be supported. 4G is also an all-IP (internet protocol)-based standard for both voice and data, different from 3G, which only uses IP for data, while enabling voice with a circuit-switched network. As an all-IP network, 4G is more efficient for mobile network providers to operate and optimize than managing different network technologies for voice and data.

Example of frequency-division multiplexing

Consider four frequency bands, each with a known finite bandwidth of 150 kHz and separated by three guard bands of 10 kHz each. To accommodate all the bands, the communication channel should have a capacity of (150 x 4) + (10 x 3) = 630 KHz.

FDM has two disadvantages:

First, since the various frequency bands must be separated by guard bands, there can be bandwidth wastage. Second, if there are significant nonlinearities in the transmission link, there could be crosstalk among the different signals, resulting in communication errors. This is a common problem in FDM because it uses analog signals, which are more prone to noise disruptions than digital signals.

Mbps in video bit rate

Highly optimized video from a streaming service may use 5-10 Mbps for Full HD (FHD). A cellphone may use 16-15 Mbps for FHD video. To ensure the best quality and enable editing later, a video camera may use 30-50 Mbps for the same video. Some high-quality cinema cameras may use hundreds of megabits per second.

History of 4G:

In 2008, no mobile network or cellular carrier was able to achieve the 100 Mbps speed that 4G specified, though there were competing approaches, including LTE and WiMAX (Worldwide Interoperability for Microwave Access), which aimed to bridge the gap between 3G and 4G. Sprint was among the principal backers of WiMAX, while Verizon pushed LTE. A key difference between WiMAX and LTE is that WiMAX did not make use of OFDM, which became a foundational element of all production 4G deployments over time. By 2011, Sprint changed course and began to support LTE across its network, and WiMAX began to disappear. LTE has steadily increased in speed and performance since 2011, with the 4G LTE-A technology providing cellular networks with the full 100 Mbps of network performance defined by the original IMT-Advanced specification.

What are multiplexers and demultiplexers in frequency-division multiplexing?

In FDM, a two-way communications circuit requires a mux/demux at either end. Multiplexing is used when frequencies (signals) of lower bandwidth are transmitted through a channel with a higher bandwidth. Consider a long-distance cable with a bandwidth of 3 megahertz. In theory, it should be possible to place and transmit 1,000 signals, each 3 kilohertz (kHz) wide, in the channel. The circuit that does this is the multiplexer. It accepts inputs from each individual user and generates a signal on a different frequency for each input. This results in a single, high-bandwidth, complex signal containing data from all users

What is frequency-division multiplexing (FDM)?

In frequency-division multiplexing (FDM), multiple signals are combined for transmission on a single communications line or channel, with each signal assigned to a different frequency (subchannel) within the main channel. To accommodate the successful transmission of multiple signals over a single line, FDM separates assigned bands by strips of unused frequencies called guard bands. This prevents overlapping between signal frequencies over a shared medium.

How many Mbps do I need for internet and network?

Internet providers will tell users the maximum speed of the connection in megabits per second. This is usually expressed as two numbers with download speed/upload speed. For example, 100 Mbps/20 Mbps -- i.e., 100 Mbps download and 20 Mbps upload. For example, a video streaming platform recommends having 25 Mbps for each 4K video stream, and a video conferencing service recommends 4 Mbps for each conference. If those in a home needed to watch two video streams and do a video conference, all at the same time, that would use 25 Mbps + 25 Mbps + 4 Mbps = 54 Mbps of total bandwidth; so, 100 Mbps internet would accommodate that use. For most home uses, 100 Mbps to 200 Mbps is sufficient. Local area network and Wi-Fi speeds are also expressed in Mbps. Always ensure home network speed is greater than internet speed. Most home routers are capable of Gigabit Ethernet. Gigabit Wi-Fi (802.11ac) operates at 500-800 Mbps, while Wi-Fi 6E (802.11ax) may offer speeds up to 3.6 Gbps.

MIMO's primary advantages

MIMO has a number of advantages over MISO and SIMO advanced antenna technologies: - MIMO enables stronger signals. It bounces and reflects signals so a user device doesn't need to be in a clear line of sight. - Video and other large-scale content can travel over a network in large quantities. This content travels more quickly because MIMO supports greater throughput. - Many data streams improve visual and auditory quality. They also decrease the chance of lost data packets.

Megabits per second vs. megabytes per second: What's the difference?

Megabits per second and megabytes per second (MBps) can be easily confused because they look the same, and both show data transfer speed. Megabit is always expressed with a lowercase "b," and megabyte is always expressed with an uppercase "B." The difference between megabits per second and megabytes per second is why you may see different numbers between your internet speed and actual download speeds. Suppose an internet connection is rated for 100 Mbps. The fastest file download speed is usually about 12 MBps. This is because 100 Mbps divided by 8 bits in a byte is 12.5 MBps and, in real-world applications due to overhead, a network will never be able to fully reach its maximum potential.

MIMO in LTE enables _____

More reliable transmission of data, while also increasing data rates. It separates the data into individual streams before transmission. During transmission, the data and reference signals travel through the air to a receiver that will already be familiar with these signals, which helps the receiver with channel estimation.

Extending orthogonal frequency-division multiplexing

OFDM has been further extended into what's called orthogonal frequency-division multiple access (OFDMA). OFDMA enables devices sharing the same overall channel to have the component subchannels dedicated to specific devices. Since all devices on the same channel share the same collision domain, this reduces the need for the devices to wait or take turns to receive data. This will specifically help in situations where a device needs a low, but consistent, stream of data or in situations where many devices are connected to a single base station

OFDM advantages and disadvantages

Orthogonal frequency-division multiplexing has many advantages over a single-channel data transmission approach. Primarily, OFDM is more resilient to electromagnetic interference, and it enables more efficient use of total available bandwidth because the subchannels are closely spaced. It is also more resistant to interference because several channels are available. Advanced error correction can be used to spread out the overall data and compensate for small errors. So, narrowband interference on a single subchannel will not affect the other channels, enabling the overall system to still operate. OFDM also has several advantages compared to standard frequency-division multiplexing. The radio frequency receiver is simpler in OFDM because the entire signal can be received in a single frequency selective filter and separated in software using a fast Fourier transform, while an FDM system requires a separate RF bandpass filter for each channel. It also has better overall bandwidth efficiency There are two primary disadvantages with OFDM compared to single-channel systems: OFDM systems must have closely tuned transmitters and receivers. This requires the timing on signal modulators and demodulators be closely matched and produced to tight tolerances. It also makes the system more sensitive to Doppler shift and, therefore, less effective for high-speed moving vehicles

What is orthogonal frequency-division multiplexing (OFDM)?

Orthogonal frequency-division multiplexing is a method of data transmission where a single information stream is split among several closely spaced narrowband subchannel frequencies instead of a single Wideband channel frequency. It is mostly used in wireless data transmission but may be employed in wired and fiber optic communication as well. In a traditional single-channel modulation scheme, each data bit is sent serially or sequentially one after another. In OFDM, several bits can be sent in parallel, or at the same time, in separate substream channels. This enables each substream's data rate to be lower than would be required by a single stream of similar bandwidth. This makes the system less susceptible to interference and enables more efficient data bandwidth

OFDM applications:

Orthogonal frequency-division multiplexing is used in many technologies, including the following: Cellular data. Long-Term Evolution (LTE) and 4G cellphone networks use OFDM. It is also an integral part of 5G NR cellular deployments. Wired data transmission, Asymmetric Digital Subscriber Line (ADSL), Institute of Electrical and Electronics Engineers (IEEE) 1901 powerline networking, cable internet providers. Fiber optic transmission may use either OFDM signals or several distinct frequencies as FDM.

What is tethering?

Tethering is the practice of using a mobile device (such as a smartphone) as a modem to connect another device, such as a laptop or another mobile phone to the Internet. To do so, the phone must have mobile data enabled. Tethering is one method of creating a mobile hotspot (an ad hoc wireless access point). The practice is increasingly common for travelers, out-of-office employees and those who want access to an alternative to the corporate network from within the workplace. Tethering may or may not provide affordable connectivity, depending on the user's data plan and contract. A tether is a long leash. In phone tethering, the leash is either a USB cable or a wireless Bluetooth connection.

What is the difference between 4G and 4G LTE?

The difference between 4G and 4G LTE is all about marketing and the history of the 4G specification. LTE (Long Term Evolution) was originally developed to make the transition for carriers easier from 3G to 4G. 4G was first defined by the ITU in 2008, but its speeds and technical specifications were not immediately achievable for mobile networks or mobile devices. As an interim step up from 3G, LTE provides more bandwidth than 3G, without achieving the full bandwidth network speed minimum of 100 Mbps that 4G promises. The term LTE is often used as part of marketing pitches and does not specify or imply a specific speed. Depending on the carrier, speeds range from 20 Mbps to 100 Mbps. 4G LTE-A (LTE-Advanced), however, is a specific term that is defined as enabling 100 Mbps. In effect, it is 4G, with no technical difference from it.

What role do transceivers play in a wireless communication network?

The role of a transceiver depends on its type. There are four types of transceivers used in wireless communication systems: - RF transceivers are used in baseband modems and routers for analog (over the wire) and digital transmission. They are also used in satellite communications networks. - Optical transceivers employ fiber optic transceiver technology to convert electronic signals into light signals. They are high-speed transmission devices. - Ethernet transceivers are used to link electronic devices in Ethernet circuitry. They are also known as media access units. - Wireless transceivers combine technology in Ethernet and RF transponders to improve Wi-Fi transmission speed.

SU-MIMO vs. MU-MIMO

There are two primary types of MIMO: single-user (SU) and multiuser (MU). In SU-MIMO systems, data streams can only interact with one device on the network at a time. MU-MIMO systems, therefore, outperform SU-MIMO. Issues arise with SU-MIMO when many users attempt to use the network simultaneously. If one person is uploading video and another is conferencing, the data stream will choke, causing latency, or delays, to skyrocket. On the other end of the spectrum, MU-MIMO has the advantage of being able to stream multiple data sets to multiple devices at a time.

Frequency-division multiplexing advantages and disadvantages

When FDM is used in a communications network, each input signal is sent and received at maximum speed at all times. This is its chief asset. However, if many signals are sent along a single long-distance line, larger bandwidth is required, as is careful engineering, to ensure proper system performance.

Importance of Wi-Fi 6:

Wi-Fi 6 -- also known as 802.11ax -- raised the bar for wireless connectivity by introducing several new technologies to help eliminate the limitations associated with adding more Wi-Fi devices to a network. Wi-Fi 7 is currently in development with an expected release in 2024

How does wireless broadband work?

Wireless broadband requires a wireless transceiver and wireless router or modem. A broadband service is also required as a continual expense. Wireless broadband connects homes and businesses to the internet, transmitting radio waves between the user's location and the service provider's location.

The advantage of wireless broadband over other broadband types

is that wireless broadband connections don't need to be physically tethered to a modem or router. Conceptually, think of wireless broadband as using a smartphone hotspot to provide internet service, but with dedicated equipment.

FDM is also used in the following:

radio transmissions -- commercial AM and FM TV transmissions wireless networks satellite communications cellular networks

In FDM _____

the total data stream is divided into several subchannels, but the frequencies of the subchannels are spaced farther apart so they do not overlap or interfere. With OFDM, the subchannel frequencies are close together and overlapping but are still orthogonal, or separate, in that they are carefully chosen and modulated so that the interference between the subchannels is canceled out.

How does a radio transceiver work?

the transceiver can work in half-duplex or full-duplex mode: - Half-duplex transceivers. It can either transmit or receive but not both at the same time. This is because both the transmitter and receiver are connected to the same antenna using an electronic switch. This mode is found in ham radios, walkie-talkies and other single-frequency - Full-duplex transceivers. The radio transmitter and receiver can work in parallel. Transmission and reception take place on different radio frequencies. This mode is observed in handheld and mobile two-way radios.