This document summarizes key concepts from the textbook "Computer Networks" by Andrew Tanenbaum and David Wetherall. It covers topics such as medium access control, multiple access protocols including ALOHA and CSMA, collision avoidance in wireless networks, Ethernet, fast Ethernet, gigabit Ethernet, switched networks, wireless LAN protocols and frame structure. It also discusses power management in wireless networks, quality of service, data link layer switching and virtual LANs.
TCP/IP (Transmission Control Protocol/Internet Protocol) is the basic communication language or protocol of the Internet. It can also be used as a communications protocol in a private network (either an intranet or an extranet).
TCP/IP (Transmission Control Protocol/Internet Protocol) is the basic communication language or protocol of the Internet. It can also be used as a communications protocol in a private network (either an intranet or an extranet).
The network layer is responsible for routing packets from the source to destination. The routing algorithm is the piece of software that decides where a packet goes next (e.g., which output line, or which node on a broadcast channel).For connectionless networks, the routing decision is made for each datagram. For connection-oriented networks, the decision is made once, at circuit setup time.
Routing Issues
The routing algorithm must deal with the following issues:
Correctness and simplicity: networks are never taken down; individual parts (e.g., links, routers) may fail, but the whole network should not.
Stability: if a link or router fails, how much time elapses before the remaining routers recognize the topology change? (Some never do..)
Fairness and optimality: an inherently intractable problem. Definition of optimality usually doesn't consider fairness. Do we want to maximize channel usage? Minimize average delay?
When we look at routing in detail, we'll consider both adaptive--those that take current traffic and topology into consideration--and nonadaptive algorithms.
The sender initializes the checksum to 0 and adds all data items and the checksum. However, 36 cannot be expressed in 4 bits. The extra two bits are wrapped and added with the sum to create the wrapped sum value 6. The sum is then complemented, resulting in the checksum value 9 (15 − 6 = 9).
Channelization is a multiple-access method in which the available bandwidth of a link is shared in time, frequency, or through code, between different stations. The three channelization protocols are FDMA, TDMA, and CDMA
The IEEE 802 is a family of IEEE standards dealing with Local Area Networks and Metropolitan Area Networks. The IEEE 802 family of standards is maintained by the IEEE 802 LAN/MAN Standards Committee (LMSC).
The most widely used standards are for the Bridging and Virtual Bridged LANs (802.1), Ethernet family (802.3), Token Ring (802.5) and Wireless LAN (802.11).
In the seven-layer OSI model of computer networking, media access control (MAC) data communication protocol is a sublayer of the data link layer (layer 2). The MAC sublayer provides addressing and channel access control mechanisms that make it possible for several terminals or network nodes to communicate within a multiple access network that incorporates a shared medium, e.g. an Ethernet network. The hardware that implements the MAC is referred to as a media access controller.
The MAC sublayer acts as an interface between the logical link control (LLC) sublayer and the network's physical layer. The MAC layer emulates a full-duplex logical communication channel in a multi-point network. This channel may provide unicast, multicast or broadcast communication service.
Universal mobile telecommunication System (UMTS) is actually the third generation mobile, which uses WCDMA. The Dream was that 2G and 2.5G systems are incompatible around the world.
-Worldwide devices need to have multiple technologies inside of them, i.e. tri-band phones, dual-mode phones
To develop a single standard that would be accepted around the world.
-One device should be able to work anywhere.
Increased data rate.
- Maximum 2048Kbps
UMTS is developed by 3GPP (3 Generation Partnership Project) a joint venture of several organization
3G UMTS is a third-generation (3G): broadband, packet-based transmission of text, digitized voice, video, multimedia at data rates up to 2 Mbps
Also referred to as wideband code division multiple access(WCDMA)
Allows many more applications to be introduce to a worldwide
Also provide new services like alternative billing methods or calling plans.
The higher bandwidth also enables video conferencing or IPTV.
Once UMTS is fully available, computer and phone users can be constantly attached to the Internet wherever they travel and, as they roam, will have the same set of capabilities.
The network layer is responsible for routing packets from the source to destination. The routing algorithm is the piece of software that decides where a packet goes next (e.g., which output line, or which node on a broadcast channel).For connectionless networks, the routing decision is made for each datagram. For connection-oriented networks, the decision is made once, at circuit setup time.
Routing Issues
The routing algorithm must deal with the following issues:
Correctness and simplicity: networks are never taken down; individual parts (e.g., links, routers) may fail, but the whole network should not.
Stability: if a link or router fails, how much time elapses before the remaining routers recognize the topology change? (Some never do..)
Fairness and optimality: an inherently intractable problem. Definition of optimality usually doesn't consider fairness. Do we want to maximize channel usage? Minimize average delay?
When we look at routing in detail, we'll consider both adaptive--those that take current traffic and topology into consideration--and nonadaptive algorithms.
The sender initializes the checksum to 0 and adds all data items and the checksum. However, 36 cannot be expressed in 4 bits. The extra two bits are wrapped and added with the sum to create the wrapped sum value 6. The sum is then complemented, resulting in the checksum value 9 (15 − 6 = 9).
Channelization is a multiple-access method in which the available bandwidth of a link is shared in time, frequency, or through code, between different stations. The three channelization protocols are FDMA, TDMA, and CDMA
The IEEE 802 is a family of IEEE standards dealing with Local Area Networks and Metropolitan Area Networks. The IEEE 802 family of standards is maintained by the IEEE 802 LAN/MAN Standards Committee (LMSC).
The most widely used standards are for the Bridging and Virtual Bridged LANs (802.1), Ethernet family (802.3), Token Ring (802.5) and Wireless LAN (802.11).
In the seven-layer OSI model of computer networking, media access control (MAC) data communication protocol is a sublayer of the data link layer (layer 2). The MAC sublayer provides addressing and channel access control mechanisms that make it possible for several terminals or network nodes to communicate within a multiple access network that incorporates a shared medium, e.g. an Ethernet network. The hardware that implements the MAC is referred to as a media access controller.
The MAC sublayer acts as an interface between the logical link control (LLC) sublayer and the network's physical layer. The MAC layer emulates a full-duplex logical communication channel in a multi-point network. This channel may provide unicast, multicast or broadcast communication service.
Universal mobile telecommunication System (UMTS) is actually the third generation mobile, which uses WCDMA. The Dream was that 2G and 2.5G systems are incompatible around the world.
-Worldwide devices need to have multiple technologies inside of them, i.e. tri-band phones, dual-mode phones
To develop a single standard that would be accepted around the world.
-One device should be able to work anywhere.
Increased data rate.
- Maximum 2048Kbps
UMTS is developed by 3GPP (3 Generation Partnership Project) a joint venture of several organization
3G UMTS is a third-generation (3G): broadband, packet-based transmission of text, digitized voice, video, multimedia at data rates up to 2 Mbps
Also referred to as wideband code division multiple access(WCDMA)
Allows many more applications to be introduce to a worldwide
Also provide new services like alternative billing methods or calling plans.
The higher bandwidth also enables video conferencing or IPTV.
Once UMTS is fully available, computer and phone users can be constantly attached to the Internet wherever they travel and, as they roam, will have the same set of capabilities.
OPTIMIZATION TECHNIQUES FOR SOURCE FOLLOWER BASED TRACK-AND-HOLD CIRCUIT FOR ...VLSICS Design
Since the current demand for high-resolution and fast analog to digital converters (ADC) is driving the need for track and hold amplifiers (T&H) operating at RF frequencies. A very fast and linear T&H circuit is the key element in any modern wideband data acquisition system. Applications like a cable TV or a broad variety of different radio standards require high processing speeds with high resolution. The track-and-hold (T&H) circuit is a fundamental block for analog-to digital (A/D) converters. Its use allows most dynamic errors of A/D converters to be reduced, especially those showing up when using high frequency input signals. Having a wideband and precise acquisition system is a prerequisite for today’s trend towards multi-standard flexible radios, with as much signal processing as possible in digital domain. This work investigates effect of various design schemes and circuit topology for track
and-hold circuit to achieve acceptable linearly, high slew rate, low power consumption and low noise
Hadj Ounis's most notable work is his sculpture titled "Metamorphosis." This piece showcases Ounis's mastery of form and texture, as he seamlessly combines metal and wood to create a dynamic and visually striking composition. The juxtaposition of the two materials creates a sense of tension and harmony, inviting viewers to contemplate the relationship between nature and industry.
Fashionista Chic Couture Maze & Coloring Adventures is a coloring and activity book filled with many maze games and coloring activities designed to delight and engage young fashion enthusiasts. Each page offers a unique blend of fashion-themed mazes and stylish illustrations to color, inspiring creativity and problem-solving skills in children.
This document announces the winners of the 2024 Youth Poster Contest organized by MATFORCE. It lists the grand prize and age category winners for grades K-6, 7-12, and individual age groups from 5 years old to 18 years old.
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23. Ethernet Performance
probability A that some station acquires the channel:
maximized when p = 1/k, with A → 1/e as k →∞
The probability that the contention interval has exactly j slots:
mean number of slots per contention:
slot duration = 2τ, the mean contention interval, w = 2τ/A.
w is at most 2τe ∼∼ 5.4τ.
mean frame takes P sec
The longer the cable, the longer the contention interval