Chapter 11. Flashcards
The transmit power of VoWiFi phones is typically less than other devices, why?
Because many of these devices are designed for portability and usually have a limited battery supply.
What is Real-Time Location Services? Where is it mainly used in? What piece of equipment is generally used?
- 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. Because healthcare providers, such as hospitals, have to run 24/7 shifts, and since many of the assets are shared, RTLSs can be extremely useful for tracking equipment that may be necessary in an emergency or for identifying the closest doctor or specialist.
- RFID’s.
What is the reason to design your network around smaller devices, such as cell phones?
Many 802.11 networks that have been in use for a few years were designed to communicate with more powerful devices such as laptop computers. 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. Handheld devices often transmit at a lower signal level than laptop computers. If a network was designed to communicate with more powerful transmitters, it is possible that a tablet or smartphone may not have sufficient power to transmit back to an access point. If this is the case, these mobile devices are likely to experience RF dead spots throughout the network. Many companies are designing their WLANs to have smaller coverage areas so that these mobile devices do not experience intermittent service.
What is wireless primary designed to do vs Ethernet, and why can wireless not yet replace the core network?
Wireless has flaws like its contention based, half duplex operation. It is designed for mobility and portability. Wireless should rarely be considered for distribution or core roles, except for building-to-building bridging or mesh backhaul.
What is one reason that you would install a wireless building-to-building bridge? What is required?
You need to provide internet access to another building, but physical fiber or coaxial is not possible.
Bridging requires that both buildings have a direct line of site, with 40% of the first fresnel zone clear
What are WISPs (Wireless Internet Service Providers)?
Deliver Internet services via wireless networking. Instead of directly cabling each subscriber, a WISP can provide services via RF communications from central transmitters.
What is a good way to get RF into a mobile unit/trailer?
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.
What are a few reason behind the need to increase density inside of classrooms?
Due to additional wall density for sound proofing, attenuation from walls is much higher.
Each student now has a laptop and potentially other wireless devices, that can quickly overwhelm APs
What is a NAC (Network Access Control)? What is it used for?
NAC can be used to “fingerprint,” or identify authentication and authorization information about devices connecting to the network. This information is then used to regulate or control the access that the user has on the network. Access can be regulated or restricted based upon many different criteria, such as time, location, access method, device type, and user
identity along with many other properties.
Do handheld devices typically need much bandwidth? What do they require?
Traditionally, they do NOT need much bandwidth, but that’s becoming less true every day, but they do need coverage areas with adequate coverage overlap for mobility (roaming).
What are the four key uses in retail locations?
- Wireless network that provides support relating to the operations of the store and the retail transactions.
- Tracking and analytics of the retail customer.
- Location-based mapping and tracking services.
- Supplemental Internet Access. Often necessitated by poor cellular coverage inside the retail establishment.
How does retail use wireless location/analytics?
Strategically placed access points or sensor devices listen for probe frames from Wi-Fi-enabled smart phones. MAC addresses are used to identify each unique device, and signal strength is used to monitor and track the location of the shopper.
What is a hotspot?
The term hotspot typically refers to a free or pay-for-use wireless network that is provided as a service by a business.
How does wireless inside of airplanes work?
Usually involves a cellular carrier router on board that communicates with cellular towers on the ground skyward facing, or via satellite uplinks.
What is FMC (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.
