- 2.Numerology? 3G4GNumerology is any belief in a divine, mystical relationship between an integer and one or more simultaneous events. It also entails the investigation of the numerical value of letters in words, names, and concepts. Along with astrology and other divinatory arts, it is frequently associated with the paranormal. From Wikipedia
- NR 5.5G (New Radio) Frame3G4G is a radio station that broadcasts in three different languages. The 5G NR Radio Frame is measured in tenths of a second. Subframes are measured in milliseconds. Slots are 14 OFDM symbols with a time interval determined by sub-carrier spacing. NTT Docomo is the source of this information.
- What is the significance of the number 8.5G in numerology?
- The term numerology refers to the configuration of waveform parameters in the context of 3GPP 5G standardization efforts, and distinct numerologies are regarded OFDM-based sub-frames with differentparameters such as subcarrier spacing/symbol duration, CP size, and so on.
- ZTE is the source of this information.
- 9.3G4G Subcarrier Spacing 15 x 2n kHz is the NR subcarrier spacing, where n can take positive numbers at the moment: n = 0, 15 x 20 = 15 kHz, n = 1, 15 x 21 = 30 kHz, n = 2, 15 x 22 = 60 kHz, n = 3, 15 x 23 = 120 kHz, n = 4, 15 x 24 = 240 kHz n will be able to take both positive and negative values in the future. n = -1, 15 x 2-1 = 7.5 kHz n = -2, 15 x 2-2 = 3.75 kHz n = -3, 15 x 2-2 = 3.75 kHz n = -3, 15 x 2-2 = 3.75 kHz n = -2, 15 x 2-2 = 3.75 kHz n = -3, 15 x 2-2 = 3.75 kHz n = -3
Why is 5G different in numerology?
Numerology (Subcarrier Spacing) can be applied to a variety of situations and purposes. The subcarrier spacing is defined in numerous locations in RRC messages for various situations and purposes, as follows. SIB1, Msg. 2/4 for initial access and SI-messages have subcarrier spacing.
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What is flexible numerology in 5G?
This is the final part of a series on the underlying technologies that will improve 5G – I previously looked at MIMO antennas and network slicing. I'm going to look at flexible numerology today. In a nutshell, flexible numerology entails innovative approaches that enable the diameter of data channels in a frequency band to be changed.
Consider how we used wireless gadgets in the past to gain a better understanding of the challenges. Anyone who has ever fiddled with an older 2.4 GHz 802.11n WiFi router may recall routing various gadgets in the home to channels 1,6 or 11. While the 2.4 GHz band has 11 different channels accessible, most wireless router makers limit use to those three to avoid cross-channel interference. They realized that if a residence just used these three channels, there would be no interference and each channel would perform at its best. The decision to employ only those three channels, on the other hand, limited the amount of bandwidth that could be used. Only three of the 11 2.4 GHz channels carried bandwidth at peak usage, therefore minimizing interference means not using much of the available frequency.
Because the FCC defines wireless frequencies as discrete channels, it's easy to think of the channels inside a wireless frequency as such. Cable companies can create distinct frequency channels inside the controlled bounds of a coaxial cable, limiting interchannel interference. However, when sent in the wild over the air, there is a lot of interference. Anyone who grew up watching television in the 1950s remembers seeing ghosts of a nearby channel when they were watching one of the lower channel numbers.
Our cellular networks are built in the same way as WiFi channels are. The FCC has designated channels inside each of the frequencies utilized for cellular service, with buffers between each channel. Even with the buffers, there is cross-channel interference between surrounding channels, therefore cellular carriers have chosen to distribute actual frequency use in ways similar to how we used channels 1,6 and 11 for WiFi.
Flexible numerology is a new 5G aim that was announced with the release of the 3GPP Release 15 standard. Flexible numerology is part of a new approach for distributing frequency that aims to make the most of the available spectrum.
The core mechanism for modulating signals in 5G will be the same as in 4G LTE – orthogonal frequency division multiplexing (OFDM). The OFDM system is the current way to try to make the best use of frequency, and it splits a data stream into several independent narrowband channels to avoid interference, similar to how we used the three WiFi channels.
Flexible numerology will allow cell sites to build significantly smaller narrowband channels inside the OFDM channels provided in the standard. This is the secret sauce that will allow 5G to communicate with a large number of devices without causing significant disturbance.
Consider the case of two users in a 5G location. The first is an IoT sensor that wants to send little amounts of data to the network, while the second is a gamer who requires large bursts of bandwidth. Both devices would be assigned a narrowband channel in the LTE network, the IoT device for a short period of time and the gaming for longer bursts. Because the IoT device is only delivering a little amount of data, this is an inefficient use of frequency. In an LTE network, even for the little time that the cell site talks with that device, the device requests the same amount of bandwidth as any other user.
Flexible numerology will allow the IoT device to be assigned a small slice of frequency. For example, the cell site might decide to dedicate 1/64th of a channel to the IoT device, leaving the remaining 63/64ths of the frequency available for other purposes while the IoT device is consuming bandwidth. In a 5G network, an IoT device might take a small slice of frequency for a brief period of time, hardly causing a ripple in the total frequency usage at the cell site.
The cellular network may treat gamers the same as it does now, but it has a slew of new choices, including flexible numerology, to boost gaming performance. It may segregate sent and received data and scale each path based on requirements. It may establish a connection for a longer period of time than usual in order to efficiently transmit the required packages. In essence, flexible numerology allows the cell site to service each consumer differently based on their individual needs.
Flexible numerology for 5G is a difficult solution that will necessitate new algorithms that will eventually be incorporated into 5G device circuits. It's always fascinating to see how new industry standards are adopted. Over the last few months, I've seen a slew of publications on the web from labs and colleges exploring the issues of flexible numerology. These findings will eventually be converted into device lab testing, and if those trials are successful, both cell sites and cellular devices will be produced. This is why a new standard like 5G can't be put in place right away. Standards identify the problem, and then scientists, engineers, and manufacturers try (or fail) to make the new ideas work. It will likely be years before flexible numerology is made to function well enough in cell sites to be used on a regular basis but if it is, frequency utilization will be considerably enhanced, which is a crucial goal for 5G.
What is numerology in wireless communication?
Returning to the headline, what does Numerology actually mean? It refers to the sub-carrier spacing formula in NR: f=15 kHz * 2n, where n is the actual number in the word numerologies.
What is subframe in 5G?
The structure of the 5G NR Frame is described on this page. It specifies a 5G frame in terms of the 3GPP NR (New Radio) standard. Subframes, slot, and symbol configurations are depicted in the 5G NR frame structure.
5G NR supports two frequency bands: FR1 (under 6GHz) and FR2 (above 6GHz) (millimeter wave range, 24.25 to 52.6 GHz).
Flexible subcarrier spacing is utilized in NR, which is evolved from the basic 15 KHz subcarrier spacing used in LTE.
G NR frame Structure
Similar to LTE technology, a frame lasts 10 milliseconds and is made up of ten subframes each lasting 1 millisecond. There are two spaces available for each subfame. 14 OFDM symbols are normally used in each slot. The 10 ms radio frames are sent one after the other in a perTDD topology. The duration of a subframe is set (i.e. 1ms), however the length of a slot varies depending on subcarrier spacing and the number of slots per subframe. It is 1 ms for 15 KHz, 500 s for 30 KHz, and so on, as illustrated below. Subcarrier spacing of 15 KHz takes up one slot every subframe, 30 KHz takes up two slots per subframe, and so on. Based on regular CP and extended CP, each slot occupies either 14 OFDM symbols or 12 OFDM symbols.
Each 5G NR frame is broken into two half frames of identical size, each with five subframes.
Subframes 0 to 4 make up half frame-0, whereas subframes 5 to 9 make up half frame-1. Before the commencement of downlink frame-i, uplink frame-i starts TTA time duration.
- A slot's OFDM symbols can be categorized as ‘downlink,' ‘flexible,' or ‘uplink.'
- Subclause 11.1 of the TS 38.213 document mentions signaling of slot formats.
- The same is mentioned in the table below.
- The UE must presume that downlink transmissions only occur in'downlink' or'flexible' symbols in a slot in a downlink frame.
- The UE may only transmit ‘uplink' or ‘flexible' symbols in a slot in an uplink frame.
- A UE that is not capable of full-duplex communication should not transmit in the uplink before NRx-Tx*Tc following the end of the last received downlinksymbol in the same cell where NRx-Tx is specified in the TS 38.101 specification.
Slot Formats in 5G NR Frame Structure (Normal CP)
A slot might be all downlink, all uplink, or mixed, as shown in the table (i.e. combination of downlink and uplink). The term “mixed” can refer to static, semi-static, or dynamic situations. Because 5G NR supports slot aggregation, data transfer can be scheduled to span one or more slots. An OFDM symbol's slot format indicates whether it is downlink, uplink, or flexible to the user equipment. The same is depicted in the diagram below.
The diagram shows a 5G NR resource grid with symbols on the time axis and subcarriers on the frequency axis.
One PRB is made up of 12 subcarriers (Physical Resource Block). In a single slot, 5G NR supports 24 to 275 PRBs. For 120 KHz subcarrier spacing, occupied BW of 34.56 MHz (minimum) and 396 MHz (highest) can be attained. In the time domain, one SS/PBCH Block takes up 4 OFDM symbols and 24 PRBs in the frequency domain. PSS and SSS, as described for LTE, are included in the 5G NR SS.
What is resource block in 5G?
In 5G, each NR Resource Block (RB) has 12 frequency-domain sub-carriers, similar to LTE. The resource block bandwidth in LTE is set at 180 KHz, but it is not in NR and is dependent on sub-carrier spacing.
What symbol is OFDM?
OFDM takes a digital information signal with bit rate Rb, translates n-bit words on to M = 2n symbols (each symbol being a complex number reflecting the amplitude and phase of an M-ary modulation scheme), and splits the resulting symbol stream (rate Rs = Rb/n) into N parallel streams.
What is CP OFDM?
The access technique for 5G New Radio is CP-OFDM. Its operation is quite similar to that of OFDM, which is utilized in LTE, except that CP-OFDM has variable subcarrier spacing, which is referred to as “numerology.” Whereas LTE has a set subcarrier separation of 15kHz, CP-OFDM can use 15kHz, 30kHz, 60kHz, 120kHz, and so on. The cyclic prefix time per symbol changes when the subcarrier spacing is adjusted.
What is subcarrier spacing in 5G?
5G modulation and framing is a considerable step forward from previous concepts. 5G NR uses ODFM as its fundamental modulation technique, just like LTE (and latest wi-fi standards, and just about any modern digital wireless system). ODFM (orthogonal frequency division multiplexing) combines many subchannels into a single channel and is believed to be both interference-resistant and frequency-efficient. It's also quite adaptable, as different numbers of subcarriers can be added to improve channel capacity or removed to provide lower-power, lower-bandwidth possibilities.
5G NR supports subcarrier spacing ranging from 15 to 240 kHz, with a maximum of 3300 subcarriers in use on a single channel. Channels must, however, be no wider than 400MHz. The standard is frequency agnostic, which means it can be used on any band with any subcarrier design. Because the channel and noise characteristics, as well as the maximum bandwidths, of the mid- and low-band frequencies below 6GHz differ significantly from those of the high-band allocations, the mid- and low-band frequencies will use 15 to 60kHz channel spacing, while the high-band frequencies will use 60 to 120kHz. Although there are no 5G band allocations between 6GHz and 24.25GHz right now, the standard enables for the best ODFM design to fit any future growth into this spectrum.
In contrast to LTE, not all devices on 5G NR must support all bandwidths. In addition, 5G NR enables adaptive bandwidth, allowing devices to switch to a low-bandwidth, low-power configuration when necessary and only ramp up to higher bandwidths when necessary. This opens the door for very low average power devices to achieve great performance for example, IoT networks, which typically only require tiny quantities of data for telemetry but must be able to update their firmware for security and feature patches. These alternative configurations are referred to as ‘bandwidth parts' in the 5G NR specification, and in theory, a device can support many bandwidth parts on the same channel at the same time, albeit the first 5G NR release limits devices to one bandwidth part at a time.
Within a subchannel, data is divided into 10 millisecond frames, which are further subdivided into ten one-millisecond subframes. Those subframes are further subdivided into 14 OFDM symbol slots. As a result, greater bandwidth subchannels have more OFDM symbols per second, resulting in shorter slots, but the core frame structure remains same. The frames are similar to LTE at the lowest subcarrier spacing, 15kHz, facilitating interoperability.
LTE and comparable systems divide bandwidth among devices into slots, but 5G NR has a technique that allows a transmission to begin within a slot, thus creating'mini-slots.' This is especially important in the upper bands, where the OFDM symbols can be rather large, and the ability to use only a few of them to transmit a reasonably short message improves both channel reuse and latency. Another benefit could be if or when 5G expands to unlicensed spectrum, which is usually subject to a ‘listen before use' guideline to avoid interference. The ability to start a transmission without waiting for a slot boundary minimizes the chance of another device taking the channel if it looks to be silent.
Other low-latency modifications in 5G NR include strong requirements for data transfers to begin immediately after a channel is authorized, as well as limits on data stream processing time. This is accomplished at the higher network layers by altering header structures so that processing can begin without knowing the entire packet's contents, and at the physical layer by having the radio receive essential information from reference and downlink control signals rather than deriving it from the symbol stream.
It's tough to say how all of 5G's promises will be fulfilled. The flexible numerology newly specified in 3GPP Release 15 is one of the main enablers for things to happen, from extreme data download speeds to self-driving cars and long-term monitoring of IoT devices. This component of 5G is critical for supporting a wide range of frequencies and scheduling for a variety of services.
1. The 15-kHz subcarrier spacing is no longer mandatory. Instead, the subcarrier spacing scales by 2 x 15 kHz to accommodate a variety of services, including QoS, latency, and frequency ranges. Lower frequency bands use 15, 30, and 60 kHz subcarrier spacing, while higher frequency bands use 60, 120, and 240 kHz subcarrier spacing.
2. As numerology () rises, the number of slots increases. Each frame is 10 milliseconds long, and each subframe is 1 millisecond long, just as LTE. A frame is made up of ten subframes. Each slot in standard CP includes 14 symbols. The number of slots in a subframe increases as numerology increases, increasing the number of symbols conveyed in a given period. When seen in Figure 1, as the frequency of the slots rises, the slot duration decreases.
3. Mini-slots for applications requiring minimal latency.
There are 14 OFDM symbols in a typical slot.
Mini-slots, on the other hand, can carry 7, 4, or 2 OFDM signals.
Mini-slots can also begin without waiting for slot boundaries, allowing for rapid delivery of low-latency payloads. Mini-slots are useful not just for low-latency applications, but they also help with LTE-NR coexistence and beamforming.
4. DL, UL, or flexible slots are available. The NR slot structure enables dynamic link direction assignment in each OFDM symbol within the slot. The network can dynamically balance UL and DL traffic as a result of this. This can be used to improve traffic for a variety of services.
5. The use of many numerologies at the same time. With a novel feature called bandwidth components, different numerologies can be communicated on the same carrier frequency. In the frequency domain, these can be multiplexed. Interference with subcarriers of another numerology can occur when different numerologies are mixed on a carrier. While this allows for several services to be provided on the same carrier frequency, it also creates additional issues in terms of interfering with each other.
Why should you be concerned?
It's like driving down a multi-lane superhighway with a lot of control.
These lanes indicate the many sorts of 5G services available. You have the fast lanes, which are extremely fast and capable of handling a large number of vehicles. You've got the slow lanes, where traffic moves at a snail's pace. Add to it a motorcycle that can swerve in and out of lanes at will. You must now be cautious about traffic and the possibility of an accident.
Flexible numerology in 5G differs significantly from 4G numerology.
It provides a great deal of flexibility, but it also poses new issues in terms of how waveforms are produced and controlled.
Subcarrier spacing, UL, DL configurations, and bandwidth portions must now be considered.
The number of test cases grows exponentially, and device designers will have to build and analyze waveforms in the frequency, time, and modulation domains, as well as check the device's network functionality using a variety of numerologies.
Look at the webcast Understanding the 5G NR Physical Layer if you want to learn more about 5G Numerology. It covers a lot of ground when it comes to the new standards, including 5G numerology, waveforms, and new access processes.
What is KPI in LTE?
Candidates for effective network planning, performance analysis, and optimization can be found in key performance indicator (KPI) data. Inadequate KPI data, on the other hand, may impede efficient network planning, resulting in rising operational costs and a negative impact on network subscribers. To that aim, this paper contains radio frequency (RF) measurements and KPI evaluations for an active 4G LTE network in Nigeria, taken at 1876.6MHz with a bandwidth of 10MHz. The RSRP, RSRQ, RSSI, SINR, PCC PHY DL Throughput, and PDCP DL Throughput are also examined during the measurements campaign. The propagation tests were conducted with a Huawei Technologies Modem E392, and the RF measurements covered three evolved node base stations (eNodeBs) with average heights of 25 meters. Site 1 (Latitude 6.43543333; Longitude 3.44539667), Site 2 (Latitude 6.55639500; Longitude 3.36693333), and Site 3 (Latitude 6.55639500; Longitude 3.36693333). (Latitude 6.51879500; Longitude 3.39911000). The E392 4G (LTE) Modem is capable of propagation measurements across several LTE frequency bands, has a 100 Mbit/s download speed, a 50 Mbit/s upload speed, uses LTE 2×2 MIMO (Multiple Input Multiple Output), and supports 64QAM (Quadrature Amplitude Modulation). The test automobile was equipped with a test terminal station, a GPS, a Windows-based computer, and the associated drive test system, as well as the Drive Test (DT) Software version-Genex prove V16 and Genex Assistance V16. The test car was driven in such a way that it took into account actual road traffic situations at a relatively low speed of up to 30 km/h with homogeneity, eliminating the possibility of Doppler effects. Data download services were initiated after establishing a terminal connection (using file transfer protocol – ftp, a drive test software, which has the function to download a large file of around 20GB). Following that, the simultaneous file download limit was increased to 5 files (such that 5 files can be downloaded simultaneously with quality download speed). When the connection dropped, the ftp software was used to re-establish a simultaneous connection, and the drive test was carried out in a scheduled cluster on a bright and sunny day. To make the interrelationships between the tested KPIs easier to understand, statistical descriptions and probability distribution functions of the KPI data are supplied, as well as dependency among the KPIs. RF planning, radio channel measurements and modeling, feasibility studies, and the design of appropriate regulatory rules for wireless communication networks could all benefit from the information presented. The data could be used by network operators for KPI analysis, radio resource management, and research and development.