INFO 620 - Final Exam Study Guide SOLUTIONS GRADE A+ GUARANTEED

________ are the end-system devices that run applications Wireless Hosts ________ networks operate in the unlicensed spectrum 802.11 ___________ is responsible for sending and receiving data (e.g. packets) to and from a wireless host Base Station _______ in cellular networks and _________ in 802.11 wireless LANs are examples of base stations Cell Towers, Access Points When a mobile host moves beyond the range of one base station and into the range of another, it will change its point of attachment, a process referred to as _____________ Handoff A Single - Hop, infrastructure - based is _________ A base station that is connected to a larger wired network A Multi - Hop, infrastructure - based are so called _______ Wireless Mesh Networks The three differences between wireless and wired networks are that wireless can have these kinds of problems:____________ , ________________ , _____________. Decreasing Signal Strength, Interference, Multi - Path Propagation If we have high ___________ then more data will get sent SNR If we have high ________ then we need a higher _______ to get more data sent BER, SNR A microwave over is considered _______ in the 2.4 GigHz Wifi frequency Noise What will allow for more data throughput? A high _______ SNR With SNR we boost the _________ to avoid BER Signal 10 to the -7th power is a good _______ number amount because it is a small number BER The hidden terminal problem refers to _____________ Two APs not seeing each other and colliding with transmissions at the same time A Chippinga is used to _______ Multiplex multiple users traffic Demultiplexing by two users is done by each user's applying their "chipping rate" __________ to the combined received signal Code The ___________ encodes the user data with a _________ rate Chipping Rate, Fewer A "Chipping Rate" code is used by the __________ lower layer protocol CDMA The Wifi Standard is __________ 802.11 The protocol used for Wifi is ____________ CSMA/CA To avoid collisions the ___________ Protocol uses __________ and ________ wait periods CSMA/CA, DIFS, SIFS _______ interval ensures that all is clear on the channel DIFS ______ interval ensures that when CRC passing frame is reached it waits before sending an ACK SIFS Current Campus Wifi architecture uses ____________ for central management of the network Controllers Perhaps the most important characteristic of video is its ___________ High Bit Rate VoIP (Voice) traffic is "loss tolerant" but "______ sensitive" Delay There are two types of compression redundancy in video: ________ , ________ Spatial, Temporal Each of the Audio samples is then rounded to one of a finite number of values is referred to as _________ Quanitzation By increasing the _______ and the number of quantization values, the decoded signal can better approximate the original analog signal Sampling Rate Speech encoding often uses _______ , with a sampling rate of 8,000 samples per second and 8 bits per sample, resulting in a rate of 64 kbps Pulse Code Modulation PBX / Routers can reduce delay effects with __________ Buffering The technique, known as _____ , avoids having to download the entire file Streaming Streaming stored video allows the user to ______ and skip forward and go back Interact By far, the most important performance measure for streaming video is ______ throughput Average Real - time conversational voice over the Internet is often referred to as _____ Voice - Over - IP Voice - Over - IP has two characteristics: _______ and loss - tolerant Delay - Sensitive For ____________ delays smaller than 150 milliseconds are not perceived by a human Voice - Over - IP Streaming video systems can use ________ or use the protocol UDP as well TCP When the video starts to arrive, the client uses _________ to provide a continuous stream to the user Buffering Delay Issues with interface buffers for VoIP can be fixed by ________ packets on queues during egress Prioritizing With UDP streaming the client sends commands regarding session state using _______ a popular protocol for such control connections RTP Firewalls deny access to most UDP ports so ________ streaming with media works better since it uses TCP as the transport protocol HTTP Firewalls use special rules called ______ to control access to the network Access Control Lists (ACL) The client can attempt to download the video at a rate higher than the consumption rate, thereby ______ video frames and put into the buffer Prefetching When the user wants to reposition HTTP Streaming video to a future point in time in the video they use ________________ CONTINUED....