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This chapter is from the book

Local Network Technology Development

We've already examined the potential bandwidth increases for the backbone and wide area networks. Development for local area networks has also been on an upward migration path.

Improvements in Ethernet technology have seen a tenfold increase in speed, and wireless local area technologies are beginning to emerge in the local arena.

Gigabit Ethernet

Both 10 Mbps and 100 Mbps Ethernet have evolved over the last 20 years to become the local networking standard because of their reliability, low cost, and ease of installation. However, streaming multimedia applications are becoming commonplace in the industry, and 100 Mbps may not be adequate in certain situations. Hence, the Gigabit Ethernet standard is born.

The 1 Gigabit Ethernet standard is already used by both corporate and government data networks. This standard does not make existing investments in current local network infrastructure obsolete. Instead, Gigabit Ethernet is designed to serve as the next progressive step for truly high speed local networking. Although Gigabit Ethernet requires fiber optic cable, there are provisions for copper twisted pair as well. Four standards that specify distance and media have been created:

  • 1000Base-SX—Standard for short-run, multimode fiber up to 550 m

  • 1000Base-LX—Standard for single-mode fiber up to 3 km

  • 1000Base-CX—Standard for twin axial copper up to 25 m long

  • 1000Base-UTP—Standard for CAT5e cable up to 100 m (uses all four pairs)

If you are looking to upgrade, local switches will require Gigabit Ethernet port connectivity. These new switches operate as a hybrid providing 10 m, 100 m, and 1000 m service.

Gigabit Ethernet provides the same packet framing and the CSMA/CD method as traditional Ethernet systems do. This affords ease of implementation and interoperability with legacy and traditional systems. Minimal training for existing staff and a familiar infrastructure make Gigabit Ethernet a sure bet for an organization deciding to upgrade a local data network.

Before we leave this topic there's just one more thing.

10 Gigabit Ethernet service is also currently in development. 10 Gigabit Ethernet is the next phase of the Ethernet evolutionary cycle. This technology will work with fiber only and will provide the same functionality as 1 Gigabit Ethernet does at 10 times the speed.


If you take a look at a desktop PC, there are wires connected to a keyboard, monitor, mouse, printer, etc. Other electronic devices such as audio and video equipment have even more cables to connect external devices. Connecting devices with each other sometimes requires complex thinking and special wiring arrangements.

This is where Bluetooth comes in. Bluetooth is named after the king of Denmark (1000 A.D.) who united his country and part of Norway into a single kingdom. This technology is named after him.

Bluetooth is wireless and automatic with the potential capability to simplify electronic connections. Bluetooth will eliminate or reduce local wiring from computers to portable CD-players to audio and video equipment. Bluetooth's radio frequency transmission is at 2.45 GHz and provides a 1 MHz bandwidth for a short distance only.

Bluetooth is designed to transmit by using relatively weak signals for a short range of about 10 meters. Spread Spectrum technology is used. You'll recall from the last chapter that this technology uses frequency hopping techniques to keep security at a maximum with signal interference at a minimum.

It is estimated that the cost of Bluetooth-enabled devices will be an additional $5 to $15 for each device.

When any two Bluetooth devices come within range of each other, an electronic signal exchange occurs automatically. The devices attempt to exchange wireless radio frequency data with each other. Obviously, other Bluetooth devices cannot interfere with each other, so a personal area network (PAN) needs to be established. The PAN forms a tiny network. That way, a PC does not interfere with devices from another PC or another electronic device such as audio or video equipment.

All of this wireless connectivity occurs with little or no interactivity from the user. The technology will run at speeds up to 1 Mbps with up to three 64-Kbps voice channels or a master Bluetooth unit broadcasting to seven slave units (Figure 10.6).

Figure 10.6 Figure 10.6 Bluetooth-enabled devices.

The Bluetooth specification has been adopted by over 2000 companies worldwide, with the promise of universal connectivity. Bluetooth and the wireless Ethernet 802.3b standard can coexist, using the same frequency spectrum, according to developers of this new technology.

Only a handful of products with the Bluetooth specification are available. The Bluetooth design is extremely interesting, but there isn't much end-user experience with the technology. Until products are announced and wireless peripherals are tested, there is some uncertainty about interoperability and the features that this technology offers.

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