Chapter 9 WiFi vs WiMax

 WiMAX (Worldwide Interoperability for MIcrowave Access).

WiMax vs. WiFi
WiMax is the set of standards (IEEE 802.16 standards group) referring to the internet access technology used versus modems and DSL.  It reuses 802.3 Ethernet components, is similar to 802.11 and Ethernet technology and makes it easier to connect into Ethernet LANs.
The logical and physical topologies are a physical star and a logical bus.   It includes a central AP to which computers direct their transmissions (star) and radio frequencies shared (bus) with the computers taking turns transmitting.
Media access is controlled access for WiMax (802.11 point coordination function or PCF).
There are two types: 802.16d and 802.16e.
802.16d uses antennas 12-18 inches in size and ideally transmits 70 Mbps for 30 miles but because of noisy radio frequency ranges is reduced to 2 Mbps and only 5 miles.  The goal of this standard is wireless connection from one central access point to a set of fixed networks (office to a central office).
802.16e  is access for mobile users and is in competition with outdoor Wi-Fi and cell phone technologies  but is incompatible with both.  It provides multiple channels with 28 Mbps for 6 miles to 2.5miles.  Users would have to substitute 802.16e for their other laptop and phone chips and antennas or purchase add-on 802.16e  NICs. (1)
In fact WiFi (technically standard 802.11) and WiMax (802.16) don't compete for broadband users or applications because WiFi is widely used and WiMax was designed for different situations but could become competitive. (2)
 WiMAX  can do far more than just developing wireless networks for high speed internet. It is also refer as Wireless broadband access, which can transfer not only data, but voice data, video data etc, and at much higher rates.

Wifi is for short range data transfer, which can be with in hundreds of meters range using non licensed spectrum and used in a certain area which may not be connected to internet; it can be used for file sharing only.

WiMax is designed for long distance coverage and it covers distance in kilometers, it uses licensed spectrum and unlicensed in a point-to-point connection to the internet. In WiMax there are multiple standards of 802.16 a, b etc, so they are used for different types of access from  mobile connectivity to fixed location connections.

WiFi has introduced a quality of service similar to fixed Ethernet, where packets are priorities on their tags. This shows that quality of service (QoS) is relative to packet flow.

WiMax uses technology based on setting up connection between end users’ device and base station. Special algorithm is scheduled for specific connection and Quality of Services (QoS) parameters can be guaranteed for each flow,
 WiFi is deployed much more than WiMax because of its ease of installation and cost effectiveness and is used with in the building or room for providing internet access by third party internet service providers and public places, hotels, coffee shops have installed WiFi access points providing high speed internet to their customers. (3)
Works Cited
(1) FitzGerald, Jerry and Alan Dennis. Business Data Communications and Networking.  2009. John Wiley and Sons, Inc. 111 River Street, Hoboken, New Jersey 07030.  P. 241-242.                                                                                                                                                                                                                                                                            
(2)  http://www.circleid.com/posts/92208_wimax_vs_wifi/
(3)  http://www.wifinotes.com/wimax/wimax-vs-wifi.html

Chapter 8 Infiniband

Infiniband
 InfiniBand is a type of communications link for data flow between processors and I/O devices throughput of up to 2.5 gigabytes per second and support for up to 64,000 addressable devices and includes scalability, quality of service (QoS) and failover.   InfiniBand is a server connect in high-performance computing (HPC) environments.
The serial bus can carry multiple channels of data at the same time in a multiplexing signal. InfiniBand also supports multiple memory areas, each of which can addressed by both processors and storage devices.
The InfiniBand Trade Association views the bus itself as a switch determining the route a given message follows in getting to its destination address. InfiniBand uses Internet Protocol Version 6 (IPv6) or a limitless amount of device expansion.(1)
InfiniBand uses a switched fabric topology, as opposed to a hierarchical switched network like traditional Ethernet architectures, although emerging Ethernet fabric architectures propose many benefits which could see Ethernet replace Infiniband.   Most of the network topologies are Fat-Tree (Clos), mesh or 3D-Torus. Recent papers (ISCA'10) demonstrated butterfly topologies as well.(2)
Like the channel model (mainframe) all transmission begins or ends with a channel adapter. Each processor has a host channel adapter (HCA) and each peripheral device has a target channel adapter (TCA) to exchange information that ensures security.(1)
InfiniBand transmits data in packets of up to 4 KB that are taken together to form a message. A message can be:     a direct memory access read from or, write to, a remote node (RDMA),  a channel send or receive,    a transaction-based operation (that can be reversed),   a multicast transmission, or  an atomic operation(2)
The InfiniBand specification comes from merging two competing designs, Future I/O, developed by Compaq, IBM, and Hewlett-Packard, with Next Generation I/O, developed by Intel, Microsoft, and Sun Microsystems.(1)
(1) http://searchstorage.techtarget.com/definition/InfiniBand
(2) "The InfiniBand roadmap gets redrawn". Gazettabyte. WEDNESDAY, JUNE 2, 2010 AT 3:35PM. Retrieved 2011-10-11.