Nuts and Volts - December 2010

3G AND 4G ARE HERE

3G and 4G refer to the third and fourth generations of cell phone technology. The first generation was plain old analog FM. The second generation was digital phones that expanded the subscriber capacity of cellular networks. 3G is also digital but with a greater data capability. Data means text messages, Internet, email, video, and games, and any new thing that comes along. The minimum 3G data rate is 384 kbps but most 3G services offer high rates depending on the network, the technology, environmental conditions, and other factors but is typically several megabits per second (Mbps).

3G also defines the radio and access technologies. The world’s most popular 3G technology is wideband CDMA (code division multiple access) offered by a majority of carriers worldwide. It is available in the US from AT&T and T-Mobile, as well as some of the smaller carriers. WCDMA provides a data rate to 2 Mbps. Most carriers have updated their 3G systems to a faster technology called high speed packet access (HSPA) that gives even faster rates to 7, 14, and 21 Mbps depending on the carrier’s implementation.

The other predominant 3G technology is cdma2000. Also a form of CDMA but incompatible with WCDMA, this system is used by Sprint and Verizon. It works well and has various data capabilities up to many Mbps.

The fourth generation (4G) is just getting started. It essentially means faster data rates making it a better user experience for video, games, and Internet access by cell phone. The first 4G system to go online was Sprint and Clearwire with their WiMAX technology. This is a high speed wireless system that uses orthogonal frequency division multiplexing (OFDM). It easily provides many Mbps of data speed over a wide range. You can get it now from Sprint using the HTC Evo smartphone (see Figure 2). WiMAX is also available as a high speed wireless broadband connection at home from Clear — the Clearwire data service. It is an alternative to cable TV or DSL for Internet access in many areas around the US.

The primary 4G technology is called long term evolution (LTE). Similar to WiMAX, it also uses OFDM. All the major carriers are well on their way to evolving their systems to LTE. LTE promises 50 to 100 Mbps data rates under favorable conditions. MetroPCS in the US has just launched LTE, with Verizon not too far behind. AT&T and T-Mobile will no doubt implement LTE starting in 2011. Not too many LTE phones are available yet but many are in development. The Samsung Craft is the LTE phone used by MetroPCS subscribers, but more are on the way.

Upgrading a cellular network to 4G is a huge and expensive task. It will take time and a major capital investment. Look for 4G to come along gradually with service in the major cities first, then elsewhere over time. Cell phone base stations will need to be expanded and many will get new antenna systems to accommodate the multiple antenna technology in LTE referred to as multiple input multiple output (MIMO). In addition, the backhaul connections from the base stations to the main cellular office and switches are undergoing a major upgrade. The widely used slower T1 digital telephone lines are being

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replaced with faster fiber optic cable and high speed microwave links. Overall, it will take time but it has to be done as the backhaul is the last bottleneck in the system to handle the millions of fast cell phone connections.

THE OPERATING SYSTEMS

A major feature of any personal computer is its operating system (OS). Most people have some form of Microsoft Windows like XP, Vista, or the new Windows 7. Apple users have their OS X version. A few hardy souls use Firefox or Chrome. In any case, the OS is a big deal as it affects how we use our PCs, laptops, or netbooks, and it determines what software we can run and the operations we can perform. The question is what does an OS have to do with a cell phone?

Most smartphones are so complex and have so many functions that they require an OS to manage all the memory and functions. Each of the main smartphone manufacturers has its own OS and it has become a big deal as it defines how the cell phones are used. Apple’s iPhone OS is probably the benchmark for smartphones as it has established the operational modes with icons on a touch screen and other functions like swipe and zoom. BlackBerry has its own OS, as well. However, the OS that has emerged as the one to beat is Google’s Android. It is essentially free and open software (except for patent licensing) that has been adopted by Samsung, HTC, Motorola, LG, and a few others. It may turn out to be the highest volume OS in use in another year or so.

Nokia — the highest volume cell phone manufacturer in the world — has used its own OS called Symbian. Until recently, it was the highest volume cell phone OS in the world. Now, Nokia has a new OS called MeeGo that is a joint development with Intel. It is used on their latest smartphone entry called the N8, shown in Figure 3.

So, where is Microsoft in all of this? Microsoft has had a cell phone OS from the beginning, but it has never been a dominant player. However, Microsoft is still trying. Their new Phone 7 OS for smartphones is now available and some phones are now available from Dell, Samsung, LG, and HTC with that OS. Figure 4 shows the new HTC smartphone with Windows Phone 7. It remains to be seen how well it will stand up to the iPhone and Android OSs.

You don’t have to worry about selecting an OS for your cell phone. It comes preinstalled and handles all the functions. And it defines how you use the phone, its ease, and convenience. You can update it with new versions later as they become available.