What is means by GSM BURST and its types

GSM BURST

As we know that GSM network uses time slot to transmit information and Burst is a type of information that contains in particular time slot of GSM network. Bursts are designed to fit in these time slots to transmit information. GSM consist of five bursts which are

1. Normal Burst 
2. Synchronization Burst 
3. Frequency Correction Burst 
4. Access Burst
5. Dummy Burst

1. Normal Burst

Gsm Normal Burst

Typical burst contains 114 bit of valuable information and divided into two groups 57 bits each. These bits contain signaling and user data.
Stealing flag helps to indicate special events like Handovers etc. It also helps to verify that whether the block contains data or is stolen.
Tail bits found at the start and end of data. It is used as a guard time. Tail bit are three (3) in number and set to zero and placed at the beginning and at the end of a burst.
The Guard Period (GP) helps in to avoid overlapping with other bursts that may carry some other information. The length of the Guard Period is 8.25 bits.
Training sequence has a length of 26 bits and is used to synchronizes the receivers, hence this effects multipath propagation. The Training sequence helps in adapting the receiver parameters to the current path propagation.

2. Synchronization Burst:

GSM Synchronization Burst

As its name suggests, this burst is used to synchronize Mobile Station
and BTS using a synchronization channel (SCH). The function of both Tail and Guard bit same as mention above in Normal Burst.
Coded Data tells about TDMA frame number.
Training sequence tells about base station number.
Mobile Station at first demodulates synchronization burst that's why the length is 64 bits. it helps to avoid Larger multipath delay spreads.

3. Frequency Correction Burst

Frequency Correction Burst

The most simple format of all the bursts is used for the frequency correction burst, which is transmitted only in the frequency correction channel (FCCH).
All 148 bits are coded with zeros and frequency which is a pure sine wave (GMSK modulator Produce sine wave) is transmitted that enable mobile to synchronize its frequency with the master frequency.
Frequency correction burst appears on frequency correction channel.

4. Random Access Burst:

Random Access Burst

Random Access Burst have a unique format as compare to others because of its special task. When first switched on, A mobile station (MS) uses the access burst for initial access to a BTS. The first job is to synchronize itself with BTS in frequency and time using synchronization burst.
Burst has a length of 88 bits plus 68.25 guard bits. The access burst length is set large because to make it possible that access burst appears at the BTS. It can be increased more by adding a guard band of 68.25.

5. Dummy Burst:

GSM Dummy Burst

Dummy burst contains no user data information. Dummy is used to fill out idle time slots on the channel when a user is not sending any data. Dummy burst sent by the base station on the base channel. When a mobile station is turned on, it easily discovers the base channel. The pseudo random bit sequence is used to avoid accidental confusion with frequency correction burst.

4 Things you need to Improve Coverage and Capacity in cellular system

The improvement in wireless technology increased the number of cellular users to a massive level. This results in more wireless services but the number of channels assigned to a cell is not enough to support the user in some areas like cities which are usually more populated.

To overcome this problem cellular design techniques are needed like cell splitting, Sectoring, Microcell and Repeaters for range extension to support the required number of users in such areas. However, these techniques increase the number of Base Station and sometimes also increased the number of the cluster in the coverage area.

1. Cell Splitting 
2. Sectoring
3. Microcell Zone concept
4. Repeaters

1. Cell Splitting 

This technique is used to divide a Congested cell into a smaller cell or microcell, each with its own base station. To do this we need to lower the antennas height and transmitting power. I know a question will arise in your mind that

How can cell splitting increase improve coverage and capacity in a cellular system?

The answer is cell splitting increases the number of times that channels are reused.

How?

New cells of a shorter radius were installed between the existing cells, which have its own base station installed on the corner of the cell that increases the number of channel per unit area.

Now let’s make it more clear using an example. Take a look to below image, imagine if the radius of each cell was cut in half. This will increase the number of cells approximately four times of the original cell number and it will also increase the number of clusters which increase the number of capacity and channels. Remember that during adding smaller cell also take care frequency reuse plan.

Micro-zone Cell concept

Transmitting Power for new cell

As we know that the size of the new cells is smaller, so the transmitting power also will be reduced. The power of the original cell will be cut in half as cell divided by half. You can find the transmitted power of the original cell by examining the received power (Pr) at original cell boundaries. It will help to maintain the frequency reuse plan.

Practical Scenario of cell splitting

The practical scenario of cell splitting is a bit different then it is mention above or you read somewhere on the internet. All cells cannot be split at the same time because a cell in real life is not of the same size. Even it is hard for network engineers to find the real estate of the cell to split it further. That is why network engineers take too careful to keep the distance between co-channel. Also increasing base station in a region increase the ratio of handover which is normally controlled using an umbrella approach.

A question arises can we use one large power for all newly define microcell?

The answer is simply No.

Why?

When smaller transmit power is used then many parts in the larger cell will remain left Pockets. And in the second case when a lager transmits power is used then some channel in a cell will be difficult to separate from their co-channels. In such scenario channel of old divide into two groups. One group served smaller cell and the second group is used by the larger cell for handoff purpose. The process of cell splitting continues when required more channel and one stage comes that all coverage area will be served by smaller cells.

2. Sectoring

Unlike cell splitting, Sectoring is another way to increase both capacity and coverage of the cellular system. Sectoring does not require changing cell size but it will reduce the number of clusters. As the number of cluster decreases the frequency reuse factor will increase.

To make this possible relative interface should be reduced without affecting the transmitted power. One way to reduce co-channel interface effectively is to replace Omni-directional antennas into directional antennas. The replaced directional antenna will radiate in its own specified sector which results in less interference as compared to Omni-directional antennas.

So we can define sector as

The technique used to increase system capacity and decrease co-channel interference by using directional antenna is known as sectoring.

How many Sectors does a cell have?

Normally cells are divided into three sectors (120 or 60 degrees). You can see the image below as an example where a cell is divided into three (3) and six (6) sectors.

Cell Sectoring

Remember that in sectoring, channels are dedicated to the specified sector and used within a particular sector. Now let’s understand it with an example. Take a look to below image, you will find a cell label “5” at the center of the image. It has also 3 co-channels on both left and right side center cell label “5”. Now you can see only two sectors radiate in the direction of the center cell. So this means out of 6 sectors, the center cell will experience interference on the forward link from only two left side sectors. In a practical scenario, interference can be further improved by down-tilting the antennas.

Sector Antenna Direction view

To summarize, sectoring improves coverage and capacity in a cellular system by radiating in a specific direction using directional antennas and reducing the number of clusters. However, sectoring increases the number of antennas.

The Draw Backs of Sectoring

Sectoring has also drawbacks which include an increasing number of the antenna. Also decreasing coverage area in sectoring will increase the number of handoffs. This increases the burden on the Mobile Switching Center. However, handoffs are not the real problem because several modern base stations are allowed to control handovers in a cell from one sector to another without interrupting MSC.

The major problem is the loss of traffic due to decreased trunking efficiency. Sectoring uses more than one antenna and have a dedicated specific number of channels. This breaks up results, decreasing trunking efficiency.

3. Microcell Zone Approach

This is another pretty awesome technique is used to increase capacity and improve coverage of the cellular system. As we learn sectoring increase the number of handoffs which puts an extra burden on MSC. Microcell zone technique is then presented to overcome handoffs issue. This approach is based on a microcell for seven cell reuse.

In this proposed scheme, the cell is made from the combination of many zones and the single base station. Normally 3 zones are used which shown in below image.

Microcell

These zones are connected to a single base station through Co-axial cable, Optical fiber, and a Microwave link. Mobile users received the strongest signal within the cell. Antennas in the microcell are installed at the outer edge of the cell.

Handoffs are avoided by switching channel between zone site. This means whenever a user moves from one zone to another zone within the cell, the user receives the same channel. Co-channel are reduced by replacing a large central base station to the small lower powered transmitter on the edge of the cell. The reduction of interference also increased capacity and trunking efficiency is not affected in the microcell.

4. Repeaters

In many cases, a large building, mountains or any other obstacle make it hard for the service provider to provide coverage efficiently in such areas. For the solution of such problems, a device is used known as a repeater.

Repeaters

A repeater is actually a bidirectional radio transmitter. This means that it send and receive simultaneously from a particular base station. A repeater can be installed anywhere accordingly because of its size. When repeater received a signal from the base station, it amplifies and radiates in the required coverage area.

Remember that noise and interference in the original signal also radiate along with the newly generated signal.

Note that repeater does not add capacity to the system. It is only the way to provide coverage to the area block by obstacles. It is also used to provide inside the buildings.

Reference Book:
1) Wireless Communications- Principles and Practice by Theodore S Rappaport
2) Mobile Cellular Communication Gottapu Sasibhushana Rao

Note: Bugs, Error, and Mistake found everywhere and that leads people towards success so that why if found any problem or mistake in the above article then please do comment and share it with your friends. Your comments are valuable to us ...

5 Things to Consider in a Small-Business Phone System

Small-Business Phone System

A platform where multiple phones are utilized by organizations in an interconnected fashion which permits features such as telephone transferring and handling, conference calling, telephone metering, and bookkeeping, shared and private voice mailboxes. A cell phone system may include merely a couple of phones in a tiny business till and including complex personal branch exchange (PBX) system employed by large organizations.

Phone system

Business telephone systems can work over the Public Switched Telephone Network and/or over the Internet (Internet telephony or VoIP). Business phone systems can also be carried as a presented service (mostly denoted to as a centrex), which can free businesses from having to finance inexpensive equipment.

Capacities of cell phone systems will continue to enlarge 2019. One trend that will go on is the development of communications that are merged with the applications and systems.

Companies no longer use their phone systems to make and receive phone calls. These approaches are being used for video calls, instant messaging and faxing. Research shows that being able to access their communication tools all is something employees appreciate. The study from RingCentral found while 65 percent say makes them productive, that 67 percent of workers believe it helps them reach better efficiencies.

Keeping that in mind, individuals would expect a rise in the total number of businesses adopting unified communications approaches to aid in increasing productivity and merge their communications tools.

Along with increasingly more and more businesses adopting communications systems in 2019, you may start looking to start looking for strategies to strengthen their communications supplies. Lately, as an instance 8x8 established a team messaging application and a fresh mobile program that was unified-specific was introduced by RingCentral.

When is the last time you made a major buy?

Just how long did you invest in researching options until you made your decision?

Figuring out, most people spend 15 hours researching before buying an automobile. And as soon as you purchase it, you spend more money on gas, oil changes, tire rotations, as well as other maintenance. And the value of the car begins to depreciate after you drive it off the lot.
When is the last time you've purchased a phone system?

How much time did you spend researching? 

Were you aware of what benefits and features to look for?

If you're on the marketplace for a mobile system, then it's well worth spending a while doing product research. Considering that unlike a vehicle, a telephone system can save money or even assist you in making money.

Given below are the 5 things that must be considered before choosing a small-business phone system:

1) Easy Management

Not everyone is a mechanic, so most people want a car that is easy to maintain so they don’t have to take it into the shop regularly. Likewise, most small businesses don’t have huge IT departments to manage complex communications systems. In some cases, you may have only one IT person who handles all your technology. When you purchase a new phone system:

• Inspect the back-end management and ensure that the maintenance needs slight effort.
• Check out whether it’s simple to finish day-to-day tasks like adding new lines, altering extensions, resetting passwords, etc.

Keep in mind, less time taken maintaining the phone system means you can give more time on other, more creative doings around the office.

2) Rapid Setup and Personalization

Most people desire to really go into a car dealership and drive off the lot several hours later. No one wishes to spend days with no car to drive. You ought to expect an identical task when installing a new phone system. Setting a new phone system up may be debilitating, especially if you use an even mobile system that is harder.

• Ensure that the solution you buy can be fitted rapidly, with little or no stoppage for your communications.
• Check that the phone system can be modified rapidly to meet any requirements that your small business may have.

3) Valuing for Small-business Funds

There are several small-business mobile systems to expensive enterprise-level platforms, which range from essential methods available on the market. At times that the adage “you get what you pay for" could be legitimate, so be skeptical of cheap phone systems provided by companies without IP telephony experience. At precisely the exact same time frame, you do not have the luxury of spending huge amounts of money on a communications platform. Do your homework and find a telephone system that fulfills your requirements without being overpriced. And remember to factor in reliability and maintenance (think fuel usage and oil changes) into the equation to understand that the whole value of ownership.

4) Flexibility to Raise with your Business

More than ever, organizations must become agile. One of the best ways to be agile as your small business is to employ a flexible communications strategy that can adapt along with you. Would you get a two-door coupe using a baby on the way? Verify that your mobile system vendor offers a simple migration path for upgrades. Precisely:

• Start looking for subscription certificate plans that let you upgrade your software as new versions become open to simplifying adding capacity.
• Cross-check that you can use the same IP phones if you update to a bigger system since phones are the main investment.

5) Help of a Reliable Communications Vendor

Would you buy a car from a brand you have never heard of? Business phone systems are offered by vendors, but maybe perhaps not all vendors are made equal. Your communications platform is your company's face and a telephone system are actually really significant long-term investment. It's how your employees connect to partners and clients. Ensure you are dealing with a business which will be there to encourage you to come and has experience providing reliable communications.

To maintain, and jump ahead, of these competitors, it plans to reason that most phone providers will look to better their communications' offerings.

Author’s Note:
IDeACOM® is dedicated to joining hands with businesses to manage their core business by enhancing communications. IDeACOM® bids a modified custom made “One Source” solution to all the communication requirements.

How channel are assigned to users in cellular System

Channel Assignment Strategies

As a communication student or network engineers, you must know that the radio spectrum is not enough to support the required cellular user. For this reason, a different technique like FDMA, TDMA, OFDMA, are adapted for efficient reuse of frequency having minimum interference. Channel created using these techniques also need to be assigned in proper manners. For this reason, a group of channels is allocated to each individual base station. Many techniques are adapted to assign the given channel to users because it has a huge impact on network performance. Even as I said this also helps in reduction of co-channel interference. Channels assignment method is either fix or dynamic.

Also Read:

4 things You Need To Improve Coverage

Mobile Internet Symbol in your Device 

Introduction To Generation In Mobile Communication  

 

Channel Assignment Strategies in a cellular system

1. Fixed Channel Assignment

Using this technique a set of voice channels are allocated to a cell. The user gets a channel when a call attempt is made. A user is always serving with unused channels. In case of all channels are busy then call attempt is blocked and the user needs to wait until the channel gets free. This means blocking probability in fixed channel assignment is high which degrade the network performance.

2. Borrowed Channel Assignment

This is the modified version of the fixed channel technique. In this approach, a channel is borrowed from the near base station when all channels are busy. Later this channel is returned back to the original base station when the call is ended. The borrowing process is supervised by Mobile switching center (MSC) while taking care of frequency Reuse plan.

3. Dynamic Channel Assignment

In a dynamic channel assignment technique, no channel is permanently allocated to a cell. Each time MSC allocates channels whenever a base station receives a call request. MSC takes cares of certain parameters like frequency reuse distance and cost during channel assignment processing to avoid co-channel interference and decreased the ratio of call blocking. In the dynamic channel, the allocation channel is only assigned if that channel is not used in the current cell. Also, MSC makes sure that the channel is not used within a restricted area because to avoid co-channel interference. This results in decreasing call blocking ratio and increase capacity of the cellular system. However, Dynamic channel allocation puts some load on MSC because this technique requires real-time data simultaneously like channel occupancy, traffic distribution and RSSI (radio signal strength indication). Also, this information requires space to store data.

Multiple Access Techniques in communication: FDMA, TDMA, CDMA

Multiple access techniques:

In a communication system, it is unrealistic and impossible to provide a single line to every separate user on the network. So what do we need to do? The answer is multiple access techniques. To overcome these problems different types of methods implemented to share a single limited band or channel into multiple users.

In communication, Multiplexing Techniques used to allow many users to share together a finite amount of radio spectrum. Multiple access techniques are based on multiplexing techniques. It will also reduce the cost and complexity of the network. E.g., Old telephone system uses FDMA to allow multiple calls on the single line.

Also Read:

4 things You Need To Improve Coverage

Mobile Internet Symbol in your Device 

Introduction To Generation In Mobile Communication  

 
Communication channels it can be a wireless spectrum or cable connections are of a higher price. Different varieties of channels adapted to the mobile communication system, e.g., like time slots into frequency bands, frequency channels, and clear codes.

Basic Communication access techniques are

1. FDMA
2. WDMA
3. OFDMA
4. TDMA
5. CDMA
6. SSMA
7. SDMA
8. PDMA

1) FDMA (Frequency Division Multiple Access)

is based on Frequency Division Multiplexing (FDM). It is the operation of splitting single channel or bandwidth into several bands of frequency. In this channel access scheme, every user gets a separate sub-band of frequency like in FM radio. In this system, the user transmits data onto different frequency at the same time.

It enables many users to transmit at the same time but using different frequency channels. It is necessary to keep the channel wider, to accept the signal spectra of the conveyance to propagate. FDMA is less complicated than TDMA, and it implemented in the narrow band system.

The widest cable system that is approximately placed in every home, hotel, and restaurants which provide a hundred of live TV channels through only one coaxial cable( 4 MHz - 1 GHz). This bandwidth divides into many small wide bands to carry different channels. E.g., At the first one TV station requires a single 6-MHz band.

2) WDMA (Wavelength Division Multiple Access )

based on wavelength division multiplexing (WDM) uses in fiber optic communication. At multiplexer side, multiple lights combine into a single light source and at the de-multiplexer, the light source converted again into various sources.

Using FDMA, the bandwidth of an Optical fiber can be subdivided. Different data source gets a different light frequency(referred to Wavelength, λ) to transmit. The FDMA technique in Optical Fiber is known as WDMA.

WDM

4) OFDMA (orthogonal frequency division multiplexing)

It is based on orthogonal frequency division multiplexing (OFDM) uses in the 4G mobile communication system. It is the process of accommodating many users in an assigned bandwidth using OFDM modulation technique. OFDM Split given channel into multiple separate narrow-band channels at different bands to neglect interference and cross-talk occurrence.

5) TDMA (Time Division Multiple Access)

In this channel access scheme, every user gets a separate time slot to transmit data onto a standard frequency band. It allows users to send information or data using the same frequency band but different times slot.

In digital systems, we have no place for continuous transmission because the users never use the assigned bandwidth all the time. TDMA is based on Time Division Multiplexing and uses in Global System for Mobile Communication (GSM).

The primary purpose of introducing TDMA technology is to gain capacity over FDMA system by providing one band or frequency channel to multiple users. In TDMA we add time slots in frequency band/channel so that many users can use single band/frequency.

Digital Bits transmitted in a specified time slot on a given frequency channel. Every user gets one or more than one time slot per frame, and the entire bandwidth is available to use for a finite period as long as needed. For both transmission and reception, TDMA uses a different time slot.

TDMA Frame Structure

TDMA slot must be synchronized. It uses the lower number of channel, that why interference can neglect.

6) Space-division multiple access (SDMA)

Space-division multiple access (SDMA) transmits different information in different physical areas. Examples include simple cellular radio systems and more advanced cellular systems which use directional antennas and power modulation to refine spatial transmission patterns.

7) Power-division multiple access (PDMA)

Power-division multiple access (PDMA) scheme is used to provide power to the users according to their needs. PDMA sets variable power transmission between the user in order to share the available power on the channel. For example, SCPC modems on a satellite transponder, where users get on-demand power.

References Book:

1. Frenzel, Louis E., Principles of Electronic Communication Systems, 3rd Edition, McGraw Hill, 2008.
2. Skylar, Bernard, Digital Communications, 2nd Edition, Prentice Hall, 2001.
3. https://en.wikipedia.org/wiki/Channel_access_method

Introduction to Generation in mobile Communication 2G, 3G, 4G, 5G

Generation in Mobile Communication

In our daily life Everyday, we face new technology which provides new and better performance. Now a day 4G and 5G are most trends in the telecommunication system. In this article, we will learn about the generation of mobile communication.

Generation in Mobile Communication

The first generation 1G

The first generation of mobile network technology was the first analog network.  It was a completely analog system uses Frequency Division Multiplexing Techniques-FDM and only voice call was supported. In the first generation of mobile network has no support for SMS and Internet. The first generation does not use encryption techniques, that why information carried by the first generation is not secured.

Also Read:

4 things You Need To Improve Coverage

Mobile Internet Symbol in your Device 

Learn About Network Modes  

A telephone call was the only way of communication to transmit the message to the other person. Because of low-frequency bandwidth and it used to take lots of energy to transmit data to far distance and also signal would get disturbed while reaching to the particular recipient.

Mobile phones were big and thick in size due to bigger antennas. Also, mobile phones had a lower battery life because data transmission used to take lots of energy. After 10 long years of 1G technology, 2G was launched.

Second Generation or 2G

2G or Second Generation is considered the most famous and influential in the communication world. It is also called the Global system of mobile communication (GSM).

In the era of the second generation digital-based technology introduced that uses Time Division Multiple Access (TDMA) and Code Division Multiple Access (CDMA). It brings new technology like short message service (SMS) and E-mails.

Moreover this development use in another technique like 2.5G or GPRS technology which results in increased speed of data up to 144 kbps. After some a new technology come in the front line that is known as EDGE. That brings up new services like the multimedia message and Wireless Internet WAP. The speed improves to one Mbps.

Third generation 3G

A UMTS base supported technology which provides greater speed up to 2 Mbps or slightly exceeds. Due to the third generation, a new service has added such as a video call.

3G improve as time spend, and new technology takes a step in like 3.5G and 3.7G. 3.5G technology involves HSDPA and HSUPA.

HSUPA provide data rate for uplink is 5.76 Mbit/s.

HSDPA achieve peak data rates of 14.0 Mbit/.

After 3.5G then 3.75G step in which can be named as HSPA+ technology. Due to this technology, the speed gain increases to 42.2 and 22 Mbit/s for download and upload respectively. This just makes technology impressive. It makes the communication system more reliable and efficient.

The drawback of the third generation is that two costly and the highest consumption of energy.

Fourth Generation 4G

The fourth generation or 4G is based on the standards of LTE and WiMAX, which offers speeds of up to 173 Mbps, which has been developed to reach 225 Mbps using new standards LTE-A, which enables you to download a movie at 800 MB in less than half a minute.

The fifth generation 5G

This is upcoming technology and still under test condition and might be released commercially in 2020. 5G will offer 1Gbps internet speed.

What is LIFI technology and how it work?

Light of Fidelity (LIFI)

The LIFI Stand of “Light of Fidelity.” It was first discovered by German physicist “Harald Haas” from the University of Edinburgh. It was announced in 2011 and was considered the best innovation of the year. LIFI emits visible light rays to communicate with user computer and devices. It is based on the type of LED lamps.

Lifi Working view

How LIFI Work

The working principle of LIFI is same as Fiber Optic Communications where light travels in the form of Pulses through the fiber. Here is the same scenario that data will move in the form of light pulses (Binary Number) but the Optical medium will not require. It does not use radio wave like Wi-Fi. It uses LED light for data transmission purpose. A photodetector device is necessary to decode light on the receiving side.

You can still use the internet while light decrease to some limits that it cannot be observed by eyes. but it will result in decreasing internet speed.

The speed of Lifi is 100 times greater than Wifi. The researchers measured speed for Lifi 10 Gbps while Wifi provides 100 Mbps. Wow, imagine data transfer with such speed. You can still use the internet while light decrease to some limits that it cannot be observed by eyes. but it will result in decreasing internet speed. Lifi uses the regular light bulb as a router to transmit its information. Lifi provides the same speed all the time as compare to Wifi because it depends on light and Wifi uses radio wave which does not remain stable all time.

The Advantages of LIFI

1) Safety

One of the main benefits of LIFI over wifi is that its area of the internet is limited to the field of light. This becomes harder for a hacker to reach your network. In the case of WIFI, radio waves spread all around and hard to control, this becomes easier for a hacker to spy on your network.

2) Speed

LIFI provide 100 times better the wifi because LIFI uses the frequency of waves is 1000 time greater than the frequency of radio wave uses by WIFI. It's mean that you can play online HD videos and high-quality Graphic games etc.

3) Costs

Lifi does not need any specialized equipment that cost you a lot. Because it does not require significant infrastructure or larger towers etc.

4) Restricted Areas

In some sensitive area like hospital, airplanes, factories people are restricted from the use of the internet because radio wave can cause damage. LIFI technology solves this problem and allows us to use the internet in such sensitive areas without causing any damage.

The Disadvantages of LIFI

1) Range

Now let start discussing the weakness of LIFI. One of the main drawbacks is Range. LIFI cannot penetrate walls, so if you are outside of the room, you will not access the internet.

Keep in mind that not only walls interrupt the signal you should also care about everything that stops passing LED bulb light through it. That way we will short of range using LIFI.

2) Another Light Source

The second disadvantage of LIFI is another light source. If you placing LIFI in such place where light can reach from outside or within a room, so there is a chance of interference.

3) Late Night User

The last disadvantage is especially for Gammer and late night internet users. They will not enjoy the internet at night because by dimming the lights will reduce the internet speed. That's why you should keep bright full brighter to access the fast internet.