close

Computers & Technology

Computers & Technology

Discover the many joys and pleasures of playing a crime game online

Discover the many joys and pleasures of playing a crime game online

Bring action and adventure to your evenings and weekends with a criminal game. One of the newest in this genre consists of a scenario that is irrepressibly fun and exciting.

The game starts with your release from prison. Having no other option and recourse, you go back to your old neighborhood. But things have changed. You are no longer on top. You come to the situation with few resources and even fewer friends. To survive you must be daring and ruthless. You must also exercise intelligence and cunning.

No act is too low, no undertaking too extreme in your quest to re-establish your place amongst the criminal gangs in the city.

One of the most thrilling and wondrous things about online MMORPG gaming is the realism that comes with it. The scenarios are drawn up based on deep insight of what it is actually like to live in a neighborhood plagued by criminals and their minions. You are forced to borrow, kill, and steal to survive. You must outmaneuver and outsmart men who are hot on your trail to end your life or return you to the penitentiary.

You should make no mistake: transforming yourself into a sly, sharp, and ambitious criminal will give you a natural high. It is something that only fantasies are made of. Downloading such a game helps you turn the deepest desire of your being into a short-lived virtual reality adventure.

You spend so much of your time seeing to the needs of others. Gaming gives you an opportunity to look after your own needs; to do some of the things you want to do. After a trying week, it can be the most pleasant of treats to get online and recreate yourself with one of the world’s most played crime games.

Gaming also gives you a chance to showcase your skill and intelligence. Mastering the tactics and techniques of your favorite game can be a great way of proving to yourself what you can do. You can find not only a source of recreation, but a point of strengthening and morale support by playing such games. Having so many games at your disposal online can be comforting, because once you’ve tired of a particular game you can simply move on to a new one.

Having the ability to review and sort through so much online fun is much more manageable by using certain online sites. These single point forums can provide you a list of great virtual games that will thrill you for hours.

Playing a criminal game amounts to taking a vacation from the world around you. It gives you a chance to take a break from the cares of the world. The time you spend climbing up and conquering the criminal underworld is time you don’t spend thinking about the troubles and difficulties of your everyday life. It is a genuine break from all that is known, familiar, and worrisome. It is also the most tremendous fun. If you are looking for the ultimate means of relaxation, then you should download and play a criminal game.

Are you looking for high-end, high quality entertainment? See how a criminal game can help you find what you seek. Get the information you need by visiting our website.

 

read more
Computers & Technology

Technology in China : WeChat sent 46 billion electronic Hongbao

Technology in China

46B electronic ‘red envelopes’ sent over Chinese New Year Chinese speculators land at the Shanghai Stock Trade as they go almost a bloom tree containing customary red envelopes containing cash for good fortunes in Shanghai 28 February 2007. More Chinese are swinging to electronic ‘red envelopes’ called hong bao to send cash amid the lunar new year. AFP

BEIJING, China — Chinese traded billions of electronic “red envelopes” over the Lunar New Year occasion, state media said Saturday, as more individuals swung to cutting edge innovation to play out the old convention of giving out money.

For a considerable length of time guardians, relatives and managers have appropriated red paper envelopes containing cash, known as “hong bao”, to youngsters or humble specialists to praise the beginning of the new year.

Be that as it may, technically knowledgeable suppliers in China are progressively selecting to exchange cash by means of their cell phones as opposed to go to the inconvenience — and cost — of purchasing envelopes and giving them out.

Ad

Around 46 billion electronic hong baos were sent or got through the prevalent informing application WeChat from January 27 — the eve of the Time of the Chicken — to February 1, the China Day by day announced.

That was 43 percent more than a year ago.

On January 27 alone more than 14 billion electronic red envelopes were exchanged on WeChat, which is possessed by web mammoth Tencent and has more than 800 million clients.

 

That was up almost 76 percent on a year ago, the daily paper stated, and incorporated a record 2,125 hong baos sent by a man in Shenzhen.

An obviously extremely well known man in the eastern region of Shandong got an amazing 10,069 envelopes.

“Hongbao is Red packets, traditionally Chinese People send this hongbao for Chinese new year or as gift. This Red Enveloppes include money”, explain this Expert of Chinese culture.

source :

Reuters

Dx Consulting

Wechat figures

read more
Computers & Technology

Choosing the Best Small Business IT Support

techtech

Every company today depends for some reason or another about IT to complete the job, if it’s a small company, accountancy company or a self employed consultant in a particular occupation. Using technologies may be limited to the principles of communicating  including sending e-mails and files to customers or colleagues, or could be much more complicated.

Whatever it’s necessary for, every business wants some type of IT support set up so that you can fix issues when things fail. This can be regarded as particularly essential for smaller businesses, because they may fight to locate the cover an inhouse supplier of the type of tech support.

Keeping this in mind, you should do extensive investigation before trying to find small business information technology support, as this can make sure that every firm finds an excellent fit in their opinion. Listed below are lots of guidance to follow along with when with this look for the perfect company.

The initial point to remember when trying to find an IT help provider to get a small company is the fact that it’s a good idea to try to find one which specialises online in small or medium companies. Really, every enterprise differs, and dimension comes with an important impact to the requirements and tastes of the business organization.

Because of this, locating a service supplier that’s specialist in supporting small enterprises suggests that you’re prone to wind up having an individual who understands just what your needs and worries are and can focus on them efficiently.

Should you be trying to find business IT support Melbourne to get a small business, search especially for businesses offering this and also have lots of case-studies and consumer recommendations showing it. You needs to be looking mainly to get an organization that has helped many companies that way like yours, , and it has evidence they have had the opportunity to satisfy the needs of the customers.

Still another suggestion will be to seek out IT assistance which fits your financial plan, and this can be exceptionally crucial in terms of small companies along with the one-man shop. The basis for this can be why these firms will probably not possess a big employee turnover now within their increase, and it is therefore important in order to purchase all these vital IT services.

Happily, you’ll find a number of businesses offering inexpensive however totally sufficient IT help for smaller companies, which may be an excellent reduction for anyone on a tighter budget. It ought to be mentioned which maybe not absolutely all IT assistance providers are identical on the other hand, and you’ll probably must hunt through a number of choices to locate one which combines quality having a diminished cost.

Another tip would be to locate a business which supplies a advanced level of interactive customer care, and does this throughout the communication strategies which might be best for you personally. This can be crucial, as a number of people would rather contact their assistance middle by e-mail, among the others favor by phone number.

Additionally, you should generate sure the firm can reply to your own inquiries and concerns in any way different occasions of evening through the entire week. Despite the fact that it isn’t always possible to get an honest 24/7 support – and really it is not always desired, – it’s nonetheless essential to discover one which has great office hours and some body that may give you an instant and beneficial reply all through that period.

Locating business IT assistance doesn’t have to be complex. However, it vital to find a business which has expertise coping with companies much like yours plus one which is responsive, beneficial and inexpensive. When every one of these variables have been in position, it is likely that you have located an excellent firm to give you support in your organization targets.

read more
Computers & Technology

Get Out of Debt By Utilizing Technology

Phone-protection-1

Debt is burdensome and often acts like an avalanche and quicksand all at the same time. You get buried beneath it, and as it weighs upon you, you begin to sink deeper and deeper. The smallest amount of debt can be both overwhelming and an unwelcome trigger to increasing your debt load. However, these days you are a fortune generation with all of the technology at your fingertips. Even just a few short years ago there wasn’t a fraction of the online and mobile apps available to help with ones finances that we have now.

Consider some of the popular, and most importantly, free apps available on the Google or Apple store. There are plenty that can help you set and track a budget with just a few clicks. Then there are those apps that can combine and consolidate all of your finances into one easy to view snapshot. This is where you can link in your bank accounts, investment accounts, and even the mortgage on your house to get an overall net worth picture. There are even more sophisticated apps that will help you determine if you have an adequate diversification in your portfolio, if you are fully tax advantaged, and most importantly, if you are on your way to a healthy retirement

Another great way to take advantage of technology to help your pocketbook is to simply stay home on the weekends! It’s not as bad as it sounds! Set yourself up with an enjoyable home atmosphere. You can even invite friends over for a good time. Just don’t let yourself go out and blow money on things and experiences you really will not benefit from. Instead, purchase all of the great Blu-Rays or DVDs you could ever want for far less from HMV. And with Groupon’s great discounted deals, you are sure to save tons of money. These days, a good blu-ray movie on a high definition television is often better picture quality and the size of the screens are getting much closer with time!

read more
Computers & Technology

Service Repair When it comes to an iPhone Water Damage

5water

Have you ever inadvertently drop your iPhone into a tank full of water, sink or even worse, in the toilet? Or maybe you left it in your pocket and ran your clothes through a washing machine, or perhaps you were beaten by rain. In any case, your iPhone may seem dead, but there are good chances that it can be resuscitated.

The sad fact is that recovery and repair cannot be guaranteed, but if you know what to do as soon as you drop the iPhone into water, then there are chances, many chances that you will get your amazing phone back to its original state.

Here the steps to follow in case of an iPhone water damage:

  1. We all know water and any electric device aren’t friends, so as soon as you drop it, remove it as quickly as humanly possible. The quicker you are the more chances or recovery.
  1. You must turn off the iPhone immediately, well if it’s not already off, and remove any casing, enclosures that can trap moisture. Don’t panic; just hold the lock and home button simultaneously for 5 seconds for a hard “shutdown”.
  1. Don’t forget to remove the battery, after shutdown, and don’t pull the battery before switching off, because as you know, iPhone batteries are non-replaceable. Remove headphones, chargers and other accessories available for water can quickly fill the entire parts damaging any component on your iPhone. You don’t have to remove the screen protector unless obvious water bubbles are seen.
  1. Great tip; clean it out. If your iPhone fell in the salt water, or something other than regular water, you can run it on 99 percent alcohol to flush out the residue salts and other contaminants. Believe it or not, alcohol is non-conductive liquid, so won’t cause much damage than contaminants. But remember, you are not washing it; you are just cleaning it to avoid further damages.
  1. You will have to force as much water as possible. Wrap it with a dry cloth, sleeve, paper towel and if need be, blow it in the right warm air. You can use a vacuum cleaner with discretion to suck the liquid. A point or precaution here; avoid sucking water from small parts such as SD card, SIM cards or battery. Also, don’t use the hair drier. I would also advise against shaking, banging or tapping it.
  1. Don’t take your iPhone apart, unless you are qualified to do that. iPhone and other iPod devices come with an LDI (Liquid Damage Indicator) that shows when the device was in contact with water. If you trigger LDI, you could void your warranty.
  1. Don’t turn the phone on, unless you are sure it well dry. The only way to be sure is contacting a Singapore company specializing in iPhone water damage. Try switching it after a day or two, and if it doesn’t give it few more days. Your iPhone may turn on, but there are chances that many of its components will be far from working, which is why it’s more than important to contact a professional company specializing in water damages.

 

Out of the most tested method of drying an iPhone is the use of Ziplock bag full of uncooked rice. Rice is said to be great at absorbing liquid, so can be of great help.

Choosing the right company for iPhone water damage

As noted above, the surest way to getting your iPhone back to its original state after water damage is getting a company that specializes in the same field. They will use the most moisture-absorbent substance, such as silica gel, which is much better than the rice. The Gadget Doctor is one of the best companies in Singapore that will help you recover your water damaged iPhone. They have trained and experiences technician who will make sure you get all your data in place and your phone alive without voiding your warranty.

 

With these simple steps, you phone should be up and running. Many at times iPhone water damage are beyond repair, depending on the extent of damage, and the only person who can be able to recover what is left is a professional like Gadget Doctor. If all these methods, doesn’t work, then I suggest you look into other alternatives such as an exchange or a new purchase. Irrespective of your iPhone water damage state, contact the manufacturer and see if they can help.

read more
Computers & Technology

Will 3D Printing Be the Demise of Plastic Injection Molding?

Plastic_inj_1

Some observers of the plastics manufacturing industry, especially those with a vested interest, would like to have you believe that 3D printing is going to be the demise of injection molding. While there are certainly cases where 3D printing makes sense, the reports of the death of injection molding have been greatly exaggerated.

Plastic injection molding is a tried-and-true method of production that is in no danger of going away anytime soon. It is a basic, dependable method of producing high quality plastic parts. Despite recent improvements in the technology of 3D printing and those likely to emerge in the future, the fact is that more than 80% of plastic parts used in products today have to be injection molded.

The answer to the question, “Which manufacturing method is best for my part?” is, “It depends.” It depends on variables like quantity, quality and cost.

Quantity

David Kazmer, Professor of Plastics Engineering at the University of Massachusetts Lowell, said in a published paper that 3D printing currently makes sense for the most rapid “procurement time to quantity” for a small quantity of 50 or fewer units.

So for production runs, injection molding is still the best manufacturing method, especially considering the long production time involved for 3D printing compared to injection molding.

There is an emerging “hybrid” practice of 3D printing the mold tooling inserts only, then producing the parts with injection molding. For certain limited applications, 3D printed inserts can be employed as a test mold for product development and very limited quantities. A 3D printed mold may last for typically just 60 to 180 pieces.

Kazmer’s study looked at where 3D printed tooling inserts may fit into the big picture, and concluded that there were still significant issues with both metal inserts (surface finish and machine cost) and polymer inserts (surface finish as well as poor strength and heat transfer).

Quality

One of the key limitations of 3D printing is the inability to make parts with the same physical properties as conventional injection molded parts. Although the number of various materials available for 3D printing seems to be constantly increasing, it is still limited compared to all the various plastic materials that can be molded. While a 3D printed prototype might be acceptable for evaluating its shape, there is no way to test the material characteristics if your prototype is not the same material as the production part will be.

Another issue cited in Kazmer’s study was surface finish. While the surface finish of the part may vary according to how good (expensive) the 3D printer is, it is still no match for the smooth surfaces attainable with polished steel injection molds.

Last, but certainly not least in the list of quality differences, is the issue of tolerances. Although the ability of 3D printing to hold tighter part tolerances is expected to improve with advanced process designs (like parallel printing) and optimization, today the part quality achieved in 3D printing is inferior compared to molded parts.

Cost

The overall cost of a 3D printed part compared to an injection molded part is tied to the quantity being produced, assuming the aforementioned quality issues do not preclude 3D printing as an option out of the gate. In the study at Lowell, the cost of 3D printing 300 of a certain size part was $20 each. The piece price of injection molding a million such units with a steel mold was just $1.13 each.

Another cost factor to consider is that associated with a design change in the prototyping stage. In 3D printing, there is no cost of modifying a mold for a prototype iteration. Design changes are simply made to the CAD model.

Within injection molding, design changes with a steel mold are typically easy to make and relatively inexpensive, but with aluminum molding tools, a design change may require the expense of all new tooling.

Additionally, new simulation software is now available to help resolve injection molding challenges in software – rather than through costly, time-consuming prototyping iterations. Testing molds in a virtual simulation environment cuts across communication barriers and allows designers, moldmakers, and manufacturing professionals to collaborate more efficiently and effectively, while eliminating the need for costly prototype and mold cycles.

When it comes to 3D printing versus injection molding, the best production method for your parts will become clear when you can answer these questions regarding your desired quantity, quality and cost.

read more
Computers & Technology

Achromatic versus Apochromatic Lenses in Telescopes

Achromatic versus Apochromatic Lenses in Telescopes

The concave lens is generally made from Flint glass, and also the convex from Crown glass.  They form an inadequate lens together and may Travel bring two wavelengths of sunshine right into a single focus. Apochromatic refracting contacts are created to view red, eco-friendly, and blue light wavelengths. The very first ones specified for through the German physicist, Abbe.  Some form of fluorite or extra low dispersion glass can also be used and also the ending outcome is a crisp obvious image free from the rainbow of color around it.  These kinds of refracting contacts tend to be more costly compared to achromatic contacts. Apochromatic contacts require contacts that may handle three color crossings.  The are often produced from costly fluoro-crown glass, abnormal flint glass, or transparent fluids which are utilized in the area Travel between your glass.  These more recent designs permitted for that objects to become free from color round the edges, plus they created less aberrations than achromatic contacts. Prices on these kinds of refracting contacts can run high with respect to the size aperture you’ll need.  2 to 3 inch apertures for Achromatic refractors can run between $250 to $1000.  3 to 5 inch apertures for Apochromatic refractors can run between $2000 to $10,000.  Choose which kind you’ll be using before you purchase one.  You might would like to consider the night sky or you might want to gaze in to the next universe. In 1733, an Englishman, Chester Moore Hall, produced the Achromatic refracting lens.  His design limited the colour aberrations by utilizing two bits of glass which were both ground and polished.  These contacts usually were used to see blue and red light.  However, the look doesn’t stop all Technology the rainbow of color round the images. Achromatic contacts are manufactured from a convex along with a concave lens.

read more
Computers & Technology

Accessorizing Computers

Accessorizing Computers

As computer consultants, it’s our responsibility and pursuit to make certain our customers are 100% satisfied once they go out our offices. But our responsibility is unnecessarily made harder when individuals don’t take time to find out about Travel computer add-ons and familiarize themselves using the restrictions of store-bought computer systems. Hopefully when a person finishes studying this short article, you’ll comprehend the lesson that people were attempting to educate our client: “What comes as they are is actually only a starter package.”The normal computer package has a CPU unit, keyboard, mouse, and speaker system. Which may be all right for many, but many people require in addition to that particularly in today’s “connected” society. Today’s customers require full multimedia abilities, an array of graphics tools, and lodging for that various portables we currently enjoy. These extras aren’t incorporated with “what comes as they are, Inch and the only method to have them would be to accessorize. Yesterday, we spent around three hrs attempting to convince a customer of ours that completely new computer systems just don’t come outfitted using the everything that many computer systems need inside a PC. We attempted to convince him that the completely functional computer is one that’s personalized with specifically selected software and hardware add-ons – which the pc bought at the shop does not include this stuff. Regrettably, our convincing ended up being to our avail. Our client was adamant he should not require more than included his boxed product and now we were just trying “bilk” more income from him.

To make use of this dough to create a scrumptious batch of chocolate nick snacks, we will have to “accessorize” this dough with choc chips along Travel with a little brown sugar. To make use of this dough into inside a warm loaf of sesame seed bread however, we’d have to “accessorize” the dough with yeast and sesame seed products. Based on certain requirements, adding accessories does not have to be costly.  Actually, you will get away with having to pay a small amount for added hardware and software if these add-ons are suitable for children. It’s when these add-ons are work needs or when they are required to produce works of quality for just about any other reason that they’ll become rather costly. Which expense is applicable to microphones, digital camera models, PDAs, scanning devices, video cams, and much more. No matter cost, you need to realize that add-ons may become “requirements,” which the optimum time to obtain them may be the moment you purchase a brand new computer. Waiting too lengthy to decorate may cause more problems than necessary because when you wait, producers continuously develop technology – technologies that the computer will not have the ability to accommodate later on. Once you are prepared to accessorize, the brand new items available on the market are extremely advanced for Travel the computer plus they just will not work. This can be a typical problem felt by individuals who wish to use hardware created for Home windows Vista on the Home windows XP or Home windows 2000 machine. As one example of the significance of adding accessories, we love to make use of the “plain dough” example. Let us state that a completely new computer is really a batch of plain dough – waiting to become flavored and a part of something helpful.

read more
Computers & Technology

Technology Strikes – “Internet of Things!”

76

It is very challenging to define Internet of Things precisely. However, many groups have overcome this challenge. The definition shares the idea that the first form of the Internet was about information and data created by people, while the next type of Internet is about information and data created by things.

Basically, the Internet of Things is a computing concept that refers to a future where every day physical objects will be linked to the Internet and be able to recognize themselves to other devices. The phrase is closely acknowledged with Radioactive-Frequency Identification as the system of transmission of messages, even though it also may involve other sensor technologies, wireless technologies or QR codes.

Internet of Things is important because a thing that can indicate itself digitally changes into something superior than the thing by itself. The thing no longer relates to you but is linked to objects in the environment and database information. When several objects act in unity, they are recognized as having “ambient intelligence.”

Connected Security systems, cars, electronic appliances, speaker systems, commercial surroundings, alarm clocks, vending machines, thermostats, lights in household and many more are examples of things or objects that fall into the wide range of Internet of Things.

Within the scope of the Internet of Things, there are more than 11 billion devices that are presently connected to the Internet, and researchers estimate that by 2025 there will be 27 times more connected things than people.

Irrespective of where you are in your Internet of Things excursion, we can help you comprehend the benefits of a robust linked ecosystem.

Convert your business using our expertise in digital technologies and integration to design, deploy and manage your connected ecosystem.

Decrease the time and risk of adopting with a digital transformation strategy engagement.

Quickly authenticate your Internet of Things project and potential business value with our proof-of-concept approach.

Speed up the conversion from ideas to plans with our innovative workshops.

Simultaneously, Internet of Things rises noteworthy challenges that could be an obstacle of comprehending its probable profits. Attention captivating headlines about the hacking of Internet linked devices, investigation fears, and confidentiality suspicions by this time have apprehended community’s attention. Technical encounters remain and innovative policy,legitimate and development challenges are emerging.

The phrase Internet of Things commonly refers to the situations where network connectivity and computing ability brings objects into its scope as well. Devices and everyday objects that are usually not considered computers, as it permits these devices to create, interchange and consume data with negligible human involvement. However, there is no universal definition of Internet of Things.

Predictions for the influence of Internet of Things on the Internet and economy are remarkable, with some anticipating more than 101 billion connected Internet of Things devices and a universal financial influence of more than $10 trillion by 2025.

read more
Computers & Technology

Video Streaming Protocols

3036546-poster-comcast

Video surveillance systems currently are undergoing a transition where more and more traditional analog solutions are being replaced by digital solutions. Compared with an analog video surveillance system, a digital video surveillance offers much better flexibility in video content processing or data transmission. At the same time, it, also, have ability to implement advanced features such as motion detection, facial recognition and object tracking. Applying digital systems, makes the security system capable of transmitting video through the Internet, so we need to study the different methods of video streaming over the network. Streaming is the process of playing a file while it is still downloading. Streaming video is a sequence of “moving images” that are sent in compressed form in a way that it can start being proceed before it is completely received like video clips on a Web page.

Here, some of the network protocols used in video streaming are described. The focus is on the features of most important protocols in video surveillance including TCP, UDP and RTSP.

Protocols in streaming technology:

Protocols are the rules implemented for a particular technology, which in streaming technology are used to carry message packets, and communication takes place only through them. Some of the protocols used in streaming technology are described as follows:

SDP:

SDP, standing for Session Description Protocol, used to describe multimedia sessions in a format understood by the participants over a network. The purpose of SDP is to convey information about media streams in multimedia sessions to help participants join or gather information of a particular session. In fact, SDP conveys information such as session name and purpose, times the session is active, codec format, media in the session, Information to receive those media (addresses, ports, formats and so on). A participant checks these information and takes the decision about joining a session.

SDP is aimed primarily for using in large WANs (Wide-Area Network) including the internet. However, SDP can also be utilized in proprietary LANs (Local Area Networks) and MANs (Metropolitan Area Networks).

DHCP:

Dynamic Host Configuration Protocol (DHCP) is a network protocol that enables a server to automatically assign a dynamic IP address to each device that connected to the network. By this assigning, a new device can be added to a network without the bother of manually assigning it a unique IP address. The introduction of DHCP eased the problems associated with manually assigning TCP/IP client addresses, resulting in flexibility and ease-of-use to network administrators.

DHCP is not a secure protocol, since no mechanism is built to allow clients and servers to authenticate each other. Both are vulnerable to deception, as one computer can pretend to be another.

RTP:

Real-Time Transport Protocol (RTP) is an internet protocol standard to manage the real-time transmission of multimedia data over unicast or multicast network services. In other words, RTP defines a standard packet format to deliver real-time audio and video over IP networks. RTP does not guarantee real-time delivery of data, but it provides mechanisms for the sending and receiving applications to support streaming data. It is utilized in conjunction with Real-Time Transport Control Protocol (RTCP) to ensure that monitor data delivery for large multicast networks is provided and Quality of Service (QOS) can be maintained. Monitoring is used to detect any packet loss and to compensate any delay jitter.

RTP is used extensively in communication and applications which involve streaming media such as telephony or video teleconference applications. The recent application of RTP is the introduction of VoIP (Voice over Internet Protocol) systems which are becoming very popular as alternatives to regular telephony circuits.

RTCP:

Real-Time Control Protocol (RTCP) is the control protocol that works in conjunction with RTP to monitor data delivery on large multicast network. Providing feedback on the quality of service being provided by RTP, is the RTCP’s primary function.

RTCP control packets are periodically transmitted by each participant in an RTP session to all other participants. It is important to point out that RTCP carries statistical and control data, while RTP delivers the data. RTCP statistics contain sender or receiver reports such as the number of bytes sent, packets sent, lost packets and round trip delay between endpoints. RTCP provides a way to correlate and synchronize different media streams that have come from the same sender.

RTSP:

The main protocol in streaming is Real Time Streaming Protocol (RTSP), which used to transmit stored or live media data over the IP network. It provides client controls for random access to the stream content. This application layer protocol is used to establish and control either a single or several time-synchronized streams of continuous media such as video and audio. RTSP servers use the Transport RTP in conjunction with RTCP, so that RTP acts as the transport protocol and RTCP will be applied for QOS (Quality of Service) analysis and also synchronization between video and audio streams. Consequently, RTSP can both control and deliver real-time content. The RTP and RTCP are independent of the underlying transport and network layers. In fact, RTSP is considered more than a protocol and provides a simple set of basic commands to control the video stream.

RSTP is based on the bandwidth available between the client and server so that breaks the large data into packet sized data. This, applied to live data feeds as well as stored. So, client software can play one packet, while decompressing the second packet and downloading the third media files. This enables the real-time file to be heard or viewed by the user immediately without downloading the entire media file and also without feeling a break between the data files.

Some features of the Real Time Streaming Protocol are listed as follows:

  • RTSP is capable of presenting media streams from different multimedia servers.
  • Controlling and delivering real time media between a media server and large numbers of media clients are feasible by RTSP.
  • Firewall friendly: Both application and transport layer firewalls can be easily handled by means of protocol.
  • RTSP provides on-demand access of multimedia items such as stored real time audio/video files, live real-time feeds, or stored non real time items.
  • New parameters or methods can be easily added in the protocol, so it enables extension.
  • There is appropriate control on the server. The server cannot stream to clients in any way such that the client cannot stop the streaming.
  • Frame level accuracy makes protocol more suitable for media applications.
  • RTSP allows interoperability between client-server multimedia products from multiple vendors.

HTTP:

Hypertext Transfer Protocol (HTTP), as an application-level protocol, is the set of rules to transfer files (text, graphic images, sound, video, and other multimedia files) on the web, so servers exchange information by using these rules. HTTP uses a server-client model in which the Web browser is client. When a user opens this Web browser, an HTTP command will be sent to the Web server. The browser uses HTTP, which is carried over TCP/IP to communicate to the server and retrieve Web content for the user.

It is worth mentioning that, HTTP is used for distributed, collaborative, hypermedia information system in addition to the context of World Wide Web.

RTMP:

The Real Time Messaging Protocol (RTMP) is used to transfer audio, video, and meta-data across a network. In fact, it is a system to deliver on-demand and live media to Adobe Flash applications which was developed by Adobe Systems. RTMP is a TCP-based protocol which maintains persistent connections and allows low latency communication. Splitting streams into fragments leads to delivering streams smoothly while transmitting much information. RTMP supports video in MP4 and FLV and audio in AAC and MP3.

Some advantages of RTMP include that it can do live streaming, allowing people to watch a video while it is being recorded. Also, it is capable of dynamic streaming, meaning that video quality adjusts automatically to bandwidth changes and seeking to later parts in a video is possible, which is particularly useful for longer videos. Players maintain the tiny buffer rather than downloading a video during playback, thus less bandwidth is used. RTMP streaming is able to skip forward to anywhere in a video at any point in time, so you can skip forward to what you want to see, without any unnecessary waiting. While with HTTP, only what is already in browser cache can be viewed. When RTMP is used as a protocol, host will need to have a dedicated server installed for RTMP.

However, RTMP has several disadvantages: due to streaming data to the player, the bandwidth of the connection must be larger than the data rate of the video, so if the connection drops for a couple of seconds, the stream will stutter. Also, since it uses different protocols and ports with HTTP, it is vulnerable to being blocked by firewalls. The biggest drawback is that RTMP only works in Flash and not in HTML5. Hence, it may be replaced by other streaming protocols with wider support.

TCP:

Transmission Control Protocol (TCP) is a popular transport layer protocol which is connection-oriented and it supplies a reliable byte stream to the top layer, called as the application layer. TCP has a positive acknowledgments mechanism and also provides a mechanism for congestion avoidance to reduce the transmission rate when the network becomes overloaded. TCP guarantees that all packets arrive undamaged in the correct order, reordering out-of-order packets and/or asking a retransmit of lost packets.

To ensure the reliable data delivery over the network, the TCP employs window based transmission mechanism where the sender maintains a buffer, called a sliding window, of sent data to the receiver. A receiver acknowledges received data by sending acknowledgement (ACK) packets. If a sender receives an ACK packet for the data in its window, it removes that data from the window, because it has been successfully transmitted to the receiver. TCP employs this mechanism for controlling of flow, so that a receiver can tell the sender, when it cannot process the data at the arriving rate. This mechanism also informs the sender that how much buffering space is available at the receiver’s end, in order to avoid overfilling of receiver’s buffer window.

TCP is a time-tested transport layer protocol that provides several features like reliability, flow control and congestion control. TCP is also a robust protocol because it can adapt with different network conditions.

The various function of TCP

    • Data transfer- The TCP can transfer a continuous stream of data among the users in the form of segments for transmission through the network.

 

    • Reliable delivery- The TCP must have the recovering ability from data that may be damaged, missed or may be duplicated over the network. This is done by assigning a sequence number to each segment being transmitted on the network and receiving a positive acknowledgment (ACK) on successful delivery. By using of sequence numbers, the receiver ends arrange segments in correct sequence, that may be received out of order and to avoid duplicate packets. In TCP, Damage is handled by adding a checksum to each segment which is being transferred, finally the checking is done at the receiver, and the damaged segments are then finally discarded.

 

    • Flow control- TCP provides a mechanism that helps the receiver to control the amount of data sent by the sender.

 

  • Connections- A Connection is combination of sockets, sequence numbers, and window sizes. Whenever the two processes want to communicate, their TCP’s has to first establish a connection. Once the communication is complete, the connection has to be terminated or closed.

UDP:

User Datagram Protocol (UDP) is a much simpler transport protocol. It is connectionless and provides simple capability to send datagrams between a pair of devices. It is not guaranteed for getting the data from one device to another, does not perform retries, and does not even aware if the target device has received the data successfully. UDP packets are not transmitted directly to the ‘true’ IP address of the receiving device, but are transmitted with a specific device allocated IP multicast address.

The operation of UDP protocol is so simple. When the application layer invokes UDP, the following operations are performed by UDP:

  • Encapsulates the data of users into datagrams.
  • Forwards these datagrams to the IP layer for the transmission.

On the other side, these datagrams are then forwarded to UDP from the IP layer. Then UDP removes the data from the datagram and forwards to the upper application layer. In UDP, a port is a number that specifies the application which is using the UDP service. It can be assumed as an address of the applications.

There are various applications that use UDP as their transport protocol, like Routing information protocol, Simple network management protocol, Dynamic host configuration protocol etc. Traffic of voice and video over the network is generally transmitted by using UDP protocol.

Comparison between some of protocols:

TCP is a connection-oriented protocol that creates end to end communications. When there is a connection between the sender and receiver, the data may be sent over the connection. UDP is a simple and connectionless protocol, therefore it does not set up a dedicated end to end connection between the sender and receiver before the actual communication takes place. The data transmission occurs in one direction from sender to receiver without verifying the state of the receiver.

In comparison to TCP which provides data integrity instead of delivery speed, RTP provides rapid delivery and has mechanisms to compensate any minor loss of data integrity.

It is also worth knowing that RTSP can support multicasting. You can use this protocol to deliver a single feed to many users, without having to provide a separate stream for each of them. While HTTP cannot do this; it is a true one-to-one delivery system.

Video streaming protocols for video surveillance:

IP cameras are the important application of RSTP protocol. RTSP-enabled IP cameras are important components of modern video management systems, by which user can use media player to watch the live video from anywhere. RTP and RTSP are allowed for the direct video feed capture from video surveillance IP-cameras. RTSP provides unprecedented facility of implementation and has been applied by nearly every mainstream IP-camera manufacturer in the market.

Also, today the video industry uses both of TCP and UDP, each with strengths and weaknesses when it comes to live viewing, playback, error correction, and more. In IP video, TCP and UDP may represent very similarity in dedicated surveillance networks.

MJPEG is typically transported via the TCP protocol. TCP guarantees delivery of packets by requiring acknowledgement by the receiver. Packets that are not acknowledged are retransmitted.

UDP is the preferred method for the transfer of live video streams at the Transport layer of the IP network stack. UDP is a faster protocol than TCP and for time sensitive applications (i.e. live video or VoIP), it is better to live with a video glitch caused by a dropped packet than to wait for the retransmission which TCP guarantees. However TCP is definitely more firewall friendly as some networks will block UDP video. UDP is most suitable for networks with very little packet loss and bandwidth that is guaranteed through QOS mechanisms.

MPEG-4 video is typically transmitted over UDP or RTP or RTSP. UDP does not guarantee delivery and provides no facility for retransmission of lost packets. UDP transport provides the option of IP Multicast (IPmc) delivery, where a single stream is generated by the camera may be received by multiple endpoints, the Media Servers.

On the other hand, where more than one client/viewer wants to see a live video stream in a network, multicast video should be used. Multicast video always uses UDP at the Transport layer.

It is worth knowing that, in bandwidth-limited applications such as remote viewing or cameras connected via the internet, TCP and UDP have unique advantages and disadvantages.

read more