What is meant by a super frame in the 802.15.4 Zigbee standard?

One proposed solution that allowed mobile users to maintain their IP addresses as they moved among foreign networks was to have a foreign network advertise a highly specific route to the mobile user and use the existing routing infrastructure to propagate this information throughout the network. We identified scalability as one concern. Suppose that when a mobile user moves from one network to another, the new foreign network advertises a specific route to the mobile user, and the old foreign network withdraws its route. Consider how routing information propagates in a distance-vector algorithm (particularly for the case of interdomain routing among networks that span the globe). a. Will other routers be able to route datagrams immediately to the new foreign network as soon as the foreign network begins advertising its route? b. Is it possible for different routers to believe that different foreign networks contain the mobile user? c. Discuss the timescale over which other routers in the network will eventually learn the path to the mobile users.

Earlier section discusses 802.11 mobility, in which a wireless station moves from one BSS to another within the same subnet. When the APs are interconnected with a switch, an AP may need to send a frame with a spoofed MAC address to get the switch to forward the frame properly. Why?

Suppose the IEEE 802.11 RTS and CTS frames were as long as the standard DATA and ACK frames. Would there be any advantage to using the CTS and RTS frames? Why or why not?

Consider the followting idealized LTE scenario. The downstream channel is slotted in time, across $\mathrm{F}$ frequencies. There are four nodes, A, B, C, and D, reachable from the base station at rates of 10 Mbps, 5 Mbps, 2.5 Mbps, 1 Mbps}, respectively, on the downstream channel. These rates assume that the base station utilizes all time slots available on all F frequencies to send to just one station. The base station has an infinite amount of data to send to each of the nodes, and can send to any one of these four nodes using any of the F frequencies during any time slot in the downstream sub-frame. a. What is the maximum rate at which the base station can send to the nodes, assuming it can send to any node it chooses during each time slot? Is your solution fair? Explain and define what you mean by "fair." b. If there is a fairness requirement that each node must receive an equal amount of data during each one second interval, what is the average transmission rate by the base station (to all nodes) during the downstream sub-frame? Explain how you arrived at your answer. c. Suppose that the fairness criterion is that any node can receive at most twice as much data as any other node during the sub-frame. What is the average transmission rate by the base station (to all nodes) during the subframe? Explain how you arrived at your answer.

What does it mean for a wireless network to be operating in "infrastructure mode"? If the network is not in infrastructure mode, what mode of operation is it in, and what is the difference between that mode of operation and infrastructure mode?

Consider the single-sender CDMA example in Figure. What would be the sender's output (for the 2 data bits shown) if the sender's CDMA code were (1,-1,1,-1,1,-1,1,-1) ?

A picture has a square frame that is 2 inches wide. The area of the picture is one-third of the total area of the picture and frame. What are the dimensions of the picture to the nearest quarter of an inch?

In reference frame $S^{\prime}$, two protons, each moving at $0.500 c$, approach each other head-on. Calculate the total kinetic energy of the two protons in frame $S^{\prime}$.

Evaluate the following expression by using mental math.

log 1

Using the Laplace transform (and showing the details of your work), find the current $i(t)$ in the $LC$ series circuit with voltage $v(t)$, assuming $L=1$ henry, $C=1$ farad, zero initial current and charge on the capacitor, and $v(t)=1$ if $0<t<a$ and $0$ otherwise.

The solid cylindrical rotor weighs 64.4 lb and is mounted in bearings A and B of the frame which rotates about the vertical Z-axis. If the rotor spins at the constant rate p = 50 rad/sec relative to the frame and if the frame itself rotates at the constant rate $\Omega$ = 30 rad/sec, compute the bending moment M in the shaft at C which the lower portion of the shaft exerts on the upper portion. Also compute the kinetic energy T of the rotor. Neglect the mass of the frame.

Use mental math to solve the equation.

-10 = -7 + z

the original photograph that you have measures 4inches by 6 inches. you have a frame that holds photos 8.5 inches by 11 inches. can you dilate the photo to fit the frame?