My Notes from chapter 11 of the CWNA study guide
Deployment considerations for commonly supported WLAN applications and devices Data
- Email and web browsing are two of the most common applications
- One of the most important aspects of designing a network to handle data-oriented applications is to ensure that the network design is capable of handling the amount of data that will be transferred
- Most data applications are forgiving of slight network delays, but problems can arise if there is not enough available data bandwidth
- Analyse the data requirements of your users and make sure that the data rates at which the users will connect are capable of handling the amount of data that they will be transmitting.
- Unlike data communications, voice communications are not tolerant of network delays, dropped packets, or sporadic connections
- So many differences in how vendors implement their voice products.
- Each vendor has unique guidelines for designing voice applications.
- It is important to understand the best practice methods for installing your voice system.
- Voice devices are typically handheld devices that do not transmit with as much power as laptops.
- More APs will be necessary to ensure adequate coverage.
- Typically more complex than voice
- In addition to multiple streams of data for video and voice, video often includes streams for setting up and tearing down the connection.
- In most cases, video has a higher loss tolerance than voice.
- Choppy audio during a videoconference would likely be highly disruptive, causing participants to ask the speaker to repeat what was said, whereas if the audio is clear and the video choppy, the speaker would likely be understood the first time.
- Important to identify the type of video that is being transmitted and the function or purpose of that transmission
- You need to evaluate the system or software that is transmitting the wireless video traffic to determine the type of traffic and protocols along with the network load.
- Real-Time Location Services (RTLS)
- Some have features that are built in, whereas others offer integration hooks to third-party vendors who specialize in location technology and have sophisticated software applications related to specific industry vertical markets
- Location tracking is expanding incredibly quickly as more and more uses are identified.
- RTLSs can be used to locate or track people or devices on a WLAN
- Healthcare is one of the biggest users of location-based technology
- Each RTLS vendor is unique and will be able to provide you with recommendations and best practice documents for deploying your RTLS equipment.
- Mobile devices (tablets and smartphones)
- Unlike changes in enterprise technology, which is planned and controlled by the IT department, the push for support of mobile devices is being made by the end user
- Multiple concerns arise with integrating these devices into the network:
- Making sure that the devices are capable of connecting to the network using the proper authentication
- Ensuring the use of encryption protocols along with the ability for these devices to be able to smoothly roam throughout the network without losing connectivity
- Providing network access, not only based upon the identity of the user of the device but also based upon the type of device or other device or connection characteristics
- The coverage area of any 802.11 network needs to be designed small enough so that any device can respond back to the access point with a strong enough signal.
Corporate data access and end-user mobility
- With 802.11n and 802.11ac technologies some companies are transitioning to these whilst reducing their Wired connections.
- Wall outlets are expensive somethings costing up to $200 per outlet.
- Some places in company are difficult to cable to: Warehouses, conference rooms, labs etc
- Providing continuous access and availability throughout the facility has become paramount in the past few years
- With this push toward leaner devices, Ethernet adapters have either given way to wireless radios or been bypassed all together in favour of wireless
- Wireless provides mobility, accessibility, and convenience, but if not designed and implemented properly, it can lack in performance, availability, and throughput
- Wireless should rarely be considered for distribution or core roles, except for building-to-building bridging or mesh backhaul
Network extension to remote areas
- Network extension to remote areas was one of the driving forces of home wireless networking, which also helped drive the demand for wireless in the corporate environment
- The same reasons for installing wireless networking in a home are also valid for installing wireless in
- When wireless networking equipment is installed, far fewer cables are required, and equipment placement can often be performed without affecting the aesthetics of a building offices, warehouses, and just about any other environment
- To provide network connectivity between two buildings, you can install an underground cable or fibre between the two buildings, you can pay for a high-speed leased data circuit, or you can use a building-to-building wireless bridge
- requires that the two buildings have a clear RF line of sight between them.
- The installation is typically easy for trained professionals to perform, and there are no monthly service fees after installation, because you own the equipment.
- In addition to connecting two buildings via a PTP bridge, three or more buildings can be networked together by using a PTMP solution. This is known as a hub and spoke or star
Wireless ISP (WISP)—last-mile data delivery
- Wireless Internet service providers (WISPs) deliver Internet services via wireless networking
- Instead of directly cabling each subscriber, a WISP can provide services via RF communications from central transmitters.
- WISP often use wireless technologies other than 802.11
Small office/home office (SOHO)
- Wireless networking has helped to make it easy for a SOHO employee to connect the office computers and peripheral devices together, as well as to the Internet.
- The main purpose of a SOHO 802.11 network is typically to provide wireless access to an Internet gateway
- Most SOHO wireless routers provide fairly easy-to-follow installation instructions and offer reasonable performance and security, though less than what their corporate counterparts provide.
Mobile office networking
- Mobile homes or trailer offices are used for many purposes: as temporary offices during construction or after a disaster or as temporary classrooms to accommodate unplanned changes in student population
- Mobile offices are simply an extension of the office environment
- Not permanent, it is usually easy to extend the corporate or school network to these offices by using wireless networking.
- A wireless bridge can be used to distribute wireless networking to the mobile office. If needed, an AP can then be used to provide wireless network access to multiple occupants of the office.
- When the mobile office is no longer needed, the wireless equipment can simply be unplugged and removed.
- A distributed solution using enterprise-grade WLAN routers at each branch office is a common choice
- Branch routers have the ability to connect back to corporate headquarters with VPN tunnels
- corporate VLANs, SSIDs, and WLAN security can all be extended to the remote branch offices
- The wired and wireless network access policies are therefore seamless across the entire organization
- Most companies do not have the luxury or need to have an IT employee at each branch office. Therefore, a network management server (NMS) at a central location is used to manage and monitor the entire enterprise network.
- Wireless networking can be used to provide a safe and easy way of connecting students to a school network.
- Because the layout of most classrooms is flexible (with no permanently installed furniture), installing a wired network jack for each student is not possible.
- Wireless networking enables any classroom seating arrangement to be used, without the safety risk of networking cables being strung across the floor.
- Computer tablets are quickly becoming commonplace devices in all levels of education.
- Schools typically require more access points for coverage because of the wall materials between classrooms.
- Most classroom walls are made of cinderblock to attenuate noise between classrooms.
- an access point is often needed in at least every other classroom
- Network access control (NAC) has become an integral part of many school networks. NAC can be used to “fingerprint,” or identify authentication and authorization information about devices connecting to the network
Industrial—warehousing and manufacturing
- Because of the vast space and the mobile nature of the employees in these environments, companies saw the need to provide mobile network access to their employees
- Warehouse and manufacturing environments often deploy wireless handheld devices, such as bar code scanners, which are used for inventory control
- Most 802.11 networks deployed in either a warehouse or manufacturing environment are designed for coverage rather than capacity
- Wireless networks are able to provide the coverage and mobility required in a warehouse environment—and provide it cost-effectively.
- There are four key uses of wireless in retail locations:
- Wireless network that provides support relating to the operations of the store and the retail transactions
- Which is tracking analytics of the retail customer
- Location-based mapping and tracking services
- Supplemental Internet access, often necessitated by poor cellular coverage inside the retail establishment
- Retail centres, hospitals, hotels, subways, and museums (and many other types of organizations) can provide turn-by-turn directions to visitors, along with promotions, and other location-based services.
- Providing wireless access for shoppers may make for a more pleasant and satisfied shopping experience and will likely result in more sales.
Healthcare—hospitals and offices
- Data access and end-user mobility
- Need quick, secure, and accurate access to patient and hospital or clinic data, so they can react and make decisions
- Medical carts used to enter and monitor patient information often have wireless connections back to the nursing station
- VoWiFi is another common use of 802.11 technology in a medical environment, providing immediate access to personnel no matter where they are in the hospital
- RTLS solutions using 802.11 Wi-Fi tags for inventory control are also commonplace
- Rely on many forms of proprietary and industry-standard wireless communications that may have the potential of causing RF interference with 802.11 wireless networks.
- Many hospitals have designated a person or department to help avoid RF conflicts by keeping track of the frequencies and biomedical equipment used within the hospital
- Many municipalities viewed this as a way of providing service to some of their residents who could not necessarily afford Internet access
Hotspots—public network access
- The term hotspot typically refers to a free or pay-for-use wireless network that is provided as a service by a business.
- Free hotspots have drawn much attention to the 802.11 wireless industry, helping to make more people aware of the benefits of the technology.
- Most hotspot providers perform network authentication by using a special type of web page known as a captive portal.
- Fans expect and demand a complete multimedia experience when attending events, including access to replays and real-time statistics
- A well-designed stadium network can allow the venue to target sections or groups of people with directed advertisements, special offers, or customized services
- A wireless network is needed to provide event operations with services such as reliable high-speed Internet access in the press box, ticketing and point-of-sale transaction processing, and video surveillance.
- Providing Wi-Fi service to any of the transportation methods is easy. Simply install one or more access points in the vehicle.
- The primary use of these networks is to provide hotspot services for end users so that they can gain access to the Internet
- he difference between a transportation network and a typical hotspot is that the network is continually moving, making it necessary for the transportation network to use some type of mobile uplink services.
Law enforcement networks
- Many law enforcement agencies are using Wi-Fi as a supplement to their public safety wireless networks
- In addition to municipalities incorporating wireless technology into law enforcement, many are adding non-Wi-Fi-based automation to utilities through the use of supervisory control and data acquisition (SCADA) equipment.
- When a police car arrives at one of these municipal Wi-Fi hotspots, the computer in the car automatically uploads the video fi les from the data storage in the car to the central video library.
- Many rescue vehicles are being equipped with either permanently mounted Wi-Fi access points or easily deployed, self-contained portable access points that can quickly and easily blanket a rescue scene with a Wi-Fi bridge to the emergency personnel’s data network.
Fixed mobile convergence
- The goal of FMC systems is to provide a single device, with a single phone number that is capable of switching between networks and always using the lowest-cost network
- FMC devices also allow you to roam across networks, so you could initiate a phone call from within your company by using the Wi-Fi network. As you walk outside, the FMC phone would roam from the Wi-Fi network to the cellular network and seamlessly transition between the two networks.
WLAN and health
- The World Health Organization and government agencies set standards that establish exposure limits to radio waves, to which RF products must comply.
- Tests performed on WLANs have shown that they operate substantially below the required safety limits set by these organizations
- The World Health Organization has also concluded that there is no convincing scientific evidence that weak radio-frequency signals, such as those found in 802.11 communications, cause adverse health effects.
- There are many vendors in the 802.11 WLAN marketplace.