ENTERPRISE EQUIPMENT: The Ball Has Just Started

Technology Trends



Standards, Standards, and More Standards: At present, globally there are two

main types of WLAN–802.11a and 802.11b–based on the standards established by

the Institute of Electrical and Electronics Engineers (IEEE). The latter has

been around for years and is the most widely adopted, while the former was

introduced more recently and is in the nascent stage of acceptance by equipment

vendors. The significant differences between the two are that 802.11a offers a

faster connection than 802.11b and operates on spectrum that is less cluttered

than 802.11b. Then, there are newer variations on these two offerings, such as

802.11g, 802.11e and 802.11i, which in essence are enhancements to the existing

standards, offering greater compatibility, flexibility and security to Wi-Fi

networks. Theoretically, 802.11b offers a throughput of 11 Mbps (though for all

practical purposes, it is closer to 5.5 Mbps) and operates on the 2.4 GHz band,

while 802.11a offers a connection speed of 54 Mbps and runs on the 5 GHz band.

In India, the 802.11b variant of WLAN is permitted for use inside campuses

without a licence.

l 802.11g: The 802.11g

standard is a combination technology that is compatible with 802.11b and uses

the 2.4 GHz band with a data rate comparable to that of 802.11a. As 802.11a runs

on the 5 GHz band, which is regulated in India and is unlikely to be offered to

private enterprises for use at least in the near future, its deployment is out

of the question. So, enterprises can look forward to deploying 802.11g. Besides

offering five times more throughput than 802.11b, 802.11g is also backwards

compatible with 802.11b, enabling an access point built for 802.11g to connect

802.11b-based devices also. A laptop with 802.11b capability and a tablet PC

with 802.11g, for instance, can thus use the same base station.

l 802.11b: 802.11b

wireless networking consists of the stations or hubs, access points, and ports.

A station (STA) is a network node that is equipped with a wireless network

device. A personal computer with a wireless network adapter is known as a

wireless client (laptops using wireless PCI cards). Wireless clients can

communicate directly with each other or through a wireless access point (AP).

Wireless clients are mobile. A wireless access point is a wireless network node

that acts as a bridge between STAs and a wired network. The wireless AP is

similar to a cellular phone network’s base station.

Wireless clients communicate with both the wired network and other wireless

clients through wireless Aps, which are not mobile and act as peripheral bridge

devices that extend a wired network. A port is a channel of a device that can

support a single point-to-point connection. For IEEE 802.11b, a port is an

association, a logical entity, over which a single wireless connection is made.

A typical wireless client with a single wireless network adapter has one port

and can support only one wireless connection. A typical wireless AP has multiple

ports and can simultaneously support multiple wireless connections. The logical

connection between a port on the wireless client and the port on a wireless AP

is a point-to-point bridged LAN segment–similar to an Ethernet-based network

client that is connected to an Ethernet switch.

Buying tips

• Radio Survey: Enterprises must carry out a radio survey of the area
  
  it wants its WLAN to cover. A survey is important for two reasons: one, it
  
  will help an enterprise design its network better and two, it would ensure
  
  that one network’s signal does not interfere with other networks in and
  
  around the proposed deployment site. An enterprise must ensure that radio
  
  signals do not cross the defined limits within which it wants the WLAN to
  
  work.
• Site Survey and Network Design: Once the radio survey is done, the
  
  next important consideration should be the interior design structure of the
  
  site where WLAN is going to be set up. WLAN systems use radio frequencies (RF).
  
  And the distance over which RF waves can travel is not the function of the
  
  product alone. It also depends on the propagation path of RF. Even though RF
  
  waves are capable of penetrating most indoor walls and other physical
  
  obstacles, their range of coverage does depend on the indoor architecture of
  
  a building. In open spaces, each wireless LAN access hub can cover up to 300
  
  feet, while in places with physical barriers like walls, a hub may be
  
  effective only up to 130 feet. This would naturally mean that access points
  
  should be placed strategically so as to overcome all physical barriers
  
  inside the building. Otherwise, users will not be able to enjoy the
  
  advantage of mobility or roam around freely in a building with their
  
  connected laptops. The enterprise should get the site survey conducted for
  
  verifying the coverage and estimating the number of WLAN access points
  
  required at the premise. This would depend on the topology of the location
  
  and the amount of throughput required.

• Do You Really Need WLAN?: In other words, an enterprise needs to
  
  know why it should deploy WLAN. WLAN can be more beneficial and productive
  
  if it is being deployed for running applications rather than plain mobile
  
  Internet access within the campus. Also, if an enterprise knows beforehand
  
  what it will do with WLAN, it will be in a better position to calculate the
  
  RoI on it.
• Integration with Existing LAN: How an enterprise integrates WLAN
  
  with the existing wired LAN is also very important. The integration should
  
  be such that it facilitates seamless movement of a user from WLAN to wired
  
  LAN and vice versa. Also, services should be enabled on the WLAN in the same
  
  way as they have been on wired LAN.
• Security Issues: Wireless LAN networks are prone to unauthorized
  
  access, breaking of encryption, and loss of data integrity. And except for a
  
  few of the more well-known vendors of WLAN products and solutions, many do
  
  not use any accepted security standards. So, an enterprise must ensure that
  
  it deploys only those WLAN products that adhere to widely accepted and
  
  proven security standards.
• QoS: An enterprise must also ensure that any network that it
  
  deploys should have QoS built in. Among other things, this should mean that
  
  the WLAN must allow an enterprise to prioritize voice, data, and video on
  
  the network. Also, the network should be scalable.
• Manageability: Managing a WLAN network can be a challenge as the
  
  network grows and adds more and more users. An enterprise must manage WLAN
  
  in the same way it manages its traditional LAN. In other words, it must look
  
  at managing both WLAN and wired LAN together from the same platform.
• Throughput: Practically 802.11b does not support more than 5.5 Mbps
  
  bandwidth. Moreover, in a multi-user environment, this 5.5 Mbps bandwidth is
  
  shared among all the users and is not dedicated to a single user. Besides,
  
  as the user keeps moving away from a wireless LAN access hub, the bandwidth
  
  output keeps on decreasing. Naturally, all this rules out high-bandwidth
  
  applications. WLAN throughput is sufficient for applications like electronic
  
  mail exchange, access to shared peripherals like printers, Internet access,
  
  and access to multi-user databases and applications.