Monday, November 22, 2010

The Advent and Evolution of Cellular Networks

Cellular networks continue to play a growing role in the WWW. In fact, HTML5 includes several tags targeted specifically at mobile devices. Moving forward, it is clear that mobile devices are the future for both the web and computing.

1G

The first commercial mobile phone network (1G) appeared in 1979.[1] It serviced the Tokyo area of Japan. 1G was purely analog, and operated on frequencies 150MHz and above. The limited capabilities of this network meant that only voice and SMS messages could be sent. In addition, the radio was highly inefficient. Inefficieny meant that cell phones died quickly, and were unreliable. Also, because 1G was purely an analog radio technology, it was easy for people to clone their phones and eavesdrop on other’s conversations. These concerns still persist today and are the primary reason some consumers distrust mobile devices. Another big concern for consumers was the extremely high powered radios needed for the analog signals. This stemmed the concerns that mobile phones cause brain cancer, another left over concern for consumers, even with modern devices. Finally, the analog nature of the network meant that error checking on the stream was not possible, leading to low voice integrity. These issues were overcome by the 2G spectrum, which was a digital network.

2G

In 1991, the first digital 2G network was deployed. 2G was an extremely important step forward for cellular networks, and one of its main standards, GSM, still accounts for 80% of cell subscribers in the world. 2G was the first digital cell standard, which allowed for several important advantages over 1G. Digital signals are much easier to compress, which allowed for greater capacity on the network. The digital radios are also much more efficient, which means that both the handsets have greater battery life, and there could be more cell towers in a given area. Digital signals can be encrypted, which meant that cell conversations were much harder to eavesdrop on. Finally, and most importantly, digital signals allowed for the introduction of data services, such as e-mail and mobile-web.

Interestingly, the same year 2G (1991) became available is when Tim Berners-Lee published the first description of HTML, HTML Tags, available.[2] The relationship was now sealed, mobile networks and the WWW would be put on a path that will inevitably continue to grow together. 10 years later, a true packet-switched IP based mobile network was introduced.

2.5G

There was an interesting period between 2G and the release of 3G known as 2.5G. 2.5G simply meant that the standard implemented both packet-switched and circuit switched domains. 2.5G allowed speeds between 80-100 Kbit/s. This meant that users with 2.5G had comparable speed to their dial-up modems. However, 2.5G served primarily as a stepping stone to 3G, and few phones actually ever utilized this standard.

An exciting feature of 2.5G was its “always on” nature.[3] Because 2.5G had a packet-switched domain, it allowed for connections to be made only when a transaction was needed, rather than relying on sessions to carry out conversations. This meant users were served on demand, and did not require lengthy acquisition times. The main benefit that users saw was that connecting a call took far less time on 2.5G than on 2G.

2.75G

There was a final iteration between 2G and 3G. 2.75G was heavily used and very popular because of the iPhone. Another name for this type of network is “EDGE”. [4] EDGE stands for Enhanced Data Rates for GSM Evolution, and its primary advantage is its speed of up to 1Mbit/s. However, due to low capacity and poor modulation techniques, the average expected speed was only 400Kbit/s.

Many iPhone users experienced painfully slow speeds on the EDGE network, and it primarily served to push Apple and other vendors to adopt 3G even faster. AT&T was the only provider who widely published EDGE, and many of the unhappy AT&T customers have EDGE to blame.

3G

2001-2002 saw the release of 3G, strengthening the bond between mobile devices and the WWW. 3G was the first network which allowed for “smart” phones. These phones often had browsers that could browse the full WWW. Also, 3G allowed for burst speeds of up to 3.1 Mbit/s. These high speeds could compete with many peoples home cable and DSL connections. In addition to the high speeds, there were several other advantages to 3G. Security was now extremely robust, and allowed users to authenticate with the network they were connecting to. This meant that impersonation was much more difficult.

Applications of the 3G network include: Video on demand, GPS services, and mobile TV. Even video chat has been introduced. The same year that 3G was being introduced, a browser known as Mobile Explorer 3.0 was becoming popular. Unfortunately, development stopped in 2002. The browser was ahead of its time because it supported HTML, IMAP for e-mail, and javascript. It was the first true WWW experience using the mobile networks as a backbone.

One major defect with the 3G network is that it has highly fragmented standards. In the US there are primarily GSM and CDMA, the latter of which has limited global capabilities. In addition, having two different standards means that users are trapped on whichever providers use their standards. For example, a user cannot have an AT&T phone and attempt to use it on Verizon Wireless. This limitation discourages competition and stifles development of future advancements.

4G

The future of mobile networks is continually growing stronger. WiMax and LTE technologies are now being released to the public, and these networks allow for speeds up to 5x as fast as 3G. Combine those speeds with devices like the MiFi and iPad, and suddenly wired networks and desktop computers begin to lose their appeal. In addition, 4G will further the advancement of ubiquitous computing and other wireless solutions. Not surprisingly, HTML5’s development and release will coincide closely with the availability of 4G. Also, HTML5 is being designed with mobile phones in mind.

The first 4G mobile phone was recently released. It is on Sprint’s network and is the HTC Evo. However, Sprint’s 4G network is the inferior WiMax technology. Verizon and AT&T’s LTE 4G will quickly supersede WiMax. LTE is both faster and more reliable than WiMax. WiMax has poor building penetration, and as such does not perform well in cities.

In addition to the speed and reliability of LTE, a significant advantage to LTE is that it is going to use SIM cards. This means that consumers will find ways to use phones released on one network on any other LTE network. Additionally, consumers can transfer their contacts easily between phones and networks. This is important because it lowers the barriers to switching networks, which will increase competition and lead to even more advanced wireless technologies.

WWW

It is clear that mobile phones and the WWW have been set on a crash course with each other from the beginning. So what do all the advancements in the mobile space mean for the future of the WWW? For the answer to that, we look at some current releases and trends in the WWW and mobile phone industries. The most obvious example is the 2007 release of the first iPhone. This phone refreshed the entire industry, and we now have a huge Android market and new releases from Palm and Blackberry. All of these devices have one primary thing in common. They are simply small computers that happen to make phone calls as well. This means they have full access to the web and all of its content.

In addition to the hardware advancement, there are many libraries to allow people to create WWW content specifically for the mobile space. One such library is jQTouch (www.jqtouch.com). jQTouch is based on the javascript library jQuery. It allows developers to create web applications that appear and behave exactly like native iPhone or Android applications. jQTouch applications are built using only CSS, javascript, and HTML. Emulating true mobile apps using nothing but these technologies proves the close relationship of the WWW and Another mobile web HTML5 framework is called Sencha Touch (http://www.sencha.com/products/touch/index.php). The great thing about Sencha is that it is not reliant on a host library like jQTouch and jQuery. The disadvantage with relying on HTML5 is it requires a very advanced browser. For example, the current version of Firefox (3.6) doesn’t support all HTML5 features. The closest you can get is a webkit based browser, such as Safari or Chrome. Although this is a problem, many smartphones have HTML5 capable browsers, and the support will only continue to grow.

On top of the advancements in the mobile space, recent times have also seen a decline of desktop machines. Apple’s chief officer, Steve Jobs, is even quoted as comparing desktop PCs to trucks. They are something people will always need, but consumers will stop buying. If desktop PCs decline, then those customers must consume some other media. That media will be delivered via mobile networks, on top hand-held devices.

Clearly the WWW and cellular technologies have been closely related since their respective inceptions. With the upcoming releases of 4G and HTML5, it is obvious that this relationship will continue to grow. Who knows, ten years into the future, wired networks may no longer exist, and the world will share one wireless network that’s available anywhere.



[1] http://www.ideafinder.com/history/inventions/telephone.htm

[2] http://en.wikipedia.org/wiki/HTML#Origins

[3] http://www.geekinterview.com/kb/What-is-2-5G-Technology.html

[4] http://www.mobileburn.com/definition.jsp?term=2.75G

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