Taking a Look at Mobile Wireless Networks
| All BlackBerry devices, mobile phones, and many handheld computers are generally referred to as wireless devices , which simply means they can transmit and receive information over invisible radio waves without the aid of wires. Wireless devices have been around for a while, as evidenced by garage door openers, television remote controls, two-way radios, and cordless phones. What primarily distinguishes these devices from BlackBerry devices is the range of the wireless communication being carried out. More specifically , BlackBerry devices communicate over a wide area network (WAN) that spans many miles, whereas the other devices mentioned are limited to a range more easily measured in tens or hundreds of feet. Such shorter range wireless networks typically fall under the category of personal area networks (PANs) or local area networks (LANs), depending on their specific wireless range. In many ways, you can compare the networking capabilities of a BlackBerry device with those of a Wi-Fi device such as a laptop or high-end handheld computer. Like BlackBerry devices, these devices can transmit and receive complex data over a wireless network connection. However, they currently suffer from the same range problem as more primitive wireless devices such as garage door openers, even though the technology is dramatically different. Granted, Wi-Fi hubs are popping up everywhere, which is making it increasingly easier to find an access point, but the fact remains that there is no unified wide area Wi-Fi network to tap into, as there is for BlackBerry devices and mobile phones. On the other hand, the BlackBerry 7100 series devices use a relatively slow data connection as compared to Wi-Fi. It seems as if we're still a few years away from having our cake and eating it too (widespread wireless access at high speeds). Getting back to WANs, which is the type of network used by BlackBerry devices, it's important to understand where wireless WANs came from in evolving to their current form. The first generation of wireless WANs (also known as 1g for first generation ) was designed exclusively for carrying analog voice data. This network was used to considerable success in early cell phones and formed the basis for creating a market for mobile communication devices. However, the network is analog, which eliminates any decent chance of carrying out meaningful data communications beyond voice conversations. The second generation of mobile phone networks (also known as 2g for second generation ) was created as a digital network that can support both voice and data communications. 2g networks have served their purpose of putting mobile phones into the digital domain, but their communication speeds are considerably lacking. More specifically, 2g networks typically offer data speeds capped at 9.6Kbps, which is quite slow by modern computing standards. To put this in practical terms, it takes anywhere from 30 to 40 minutes to download a 3-minute MP3 song over a 2g network connection. Popular 2g networks include Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSMC), Time Division Multiple Access (TDMA), and Integrated Digital Enhanced Network (iDEN), which are still used by many mobile phones worldwide. In addition to offering digital data communications, 2g networks were a necessary replacement for 1g networks to accommodate a wider spectrum of frequencies for the rapidly growing number of mobile phone users. Confusingly, the generation of WANs after 2g isn't called 3g, as you might expect. This is because the network succeeding 2g was designed more as an incremental improvement over 2g as opposed to a full-blown next -generation network. I'm referring to the network type known as 2.5g , which improves upon the 2g data transfer limitations by offering a theoretical maximum speed of 115Kbps. Unfortunately, few if any 2.5g wireless networks offer speeds anywhere near this theoretical maximum speed. A more realistic speed range for 2.5g networks is 40Kbps60Kbps, which still represents a significant improvement over 2g networks. Going back to the MP3 download example, it takes anywhere from 6 to 9 minutes to download a 3-minute MP3 song over a 2.5g network connection. All BlackBerry 7100 series devices currently operate on the 2.5g network and have varying network speeds unique to each specific wireless service provider. The only 2.5g network is General Packet Radio Service (GPRS), which is used by many wireless providers to support most of the current mobile handheld devices that combine both voice and data communications. To make the whole 2g/2.5g/3g discussion even more confusing, there is a network standard considered to be 2.75g. I'm referring to Enhanced Data GSM Environment (EDGE), which is considered an improvement over 2g and 2.5g that offers data transfer speeds up to 384Kbps. EDGE represents an option for some wireless service providers who aren't ready or able to make the significant move up to a 3g network. The true third-generation wireless mobile network (also known as 3g ) has been around for a couple of years but is still somewhat limited in terms of provider and device support, especially in North America. 3g networks provide data transfer speeds in the range of 144Kbps2Mbps, which is a significant improvement over earlier networks. Using the MP3 download example one more time, it takes anywhere from 11 to 90 seconds to download a 3-minute MP3 song over a 3g network connection. Major 3g networks include W-CDMA (Wideband CDMA) and CDMA2000. BlackBerry currently offers two devices designed for 3g networksthe 6750 and 7750which have a much larger form factor than the 7100. Although currently no 7100 devices support 3g networks, it is likely only a matter of time before RIM expands the 7100 product line for 3g. |
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