MIMO ROUTERS - A quick summary

MIMO routers build on the MIMO technology, a relatively new set of technology protocols that reinvent the way signals are transmitted and received. MIMO routers send out multiple data streams at the same time and then use multiple antennas to sift through the signals for the requisite pattern. All this is done while maintaining a fast connection and, hence, a fast data stream. One characteristic sign of a MIMO router is multiple antennae.

Benefits of MIMO Routers. These include:
• Faster speeds.
• Greater distances between your paired devices.
• More simultaneous users.
• Less signal fading and dead spots.
• Better resistance to interference.

Concerns of MIMO Routers:

1. MIMO routers have a premium associated with them. The prices can fall as the product gets matured.
2. Pending 802.11N standard.

MIMO (Multiple Input Multiple Output) technology

1. MIMO is a new wireless technology conceived in the mid 90’s
2. It is based on an entirely new paradigm for digital signal processing that multiplies the data rate throughput achievable in wireless communication products.
3. Greatly improves the reliability, range and robustness of the connection providing a much better user experience that is closer to “wired” Ethernet quality.
4. MIMO technology is now being introduced to the Wi-Fi market.

MIMO is a smart antenna technique that increases speed, range, reliability and spectral efficiency for wireless systems.
MIMO is one technology being considered for 802.11n, a standard for next-generation 802.11 that boosts throughput to 100M bit/sec.

• Smart antenna techniques use multiple antennas to improve wireless performance and reliability.
– Antennas themselves are “dumb” pieces of metal.
– “Smartness” comes from signal processing that is applied to the multiple antennas.
– There are differing degrees of smartness.
• Conventional, “single-dimension” (1D) smart antenna techniques transmit just one data stream per channel
– RF beamforming.
– Digital beamforming.
– Digital receive diversity combining.
• MIMO makes smart antennas “multi-dimension”.
– Multiple data streams in the same channel.
– 2-D signals.

BENEFITS OF MIMO TECHNOLOGY:
For Business
• Enables truly wireless office – replaces Ethernet
– Improves wireless reliability and robustness
– Reduces infrastructure cost - Doubles coverage area of each AP
– Rates to 108 Mbps in each channel – similar to wired Ethernet speed
• Improves VoIP performance
– Extends handset battery life
– Increases call capacity
For Consumers
• One AP covers your whole home with reliable service
– Penetrates more walls at higher rates
– No need to sit in the right place to use your laptop
• Supports new wireless multimedia applications
– Whole-home coverage for high-speed broadband access
– Reliable SDTV and HDTV video transport in home networks
– Multi-service applications – voice, video, data

What are Routers, Switches, Hubs — Is There a Difference between them ?

Each device has its own function in a network environment. Two reasons confusion exists are
(1) all three are simple boxes with several plugs that accept cables and
(2) at times the functions of each device are rolled into one single device.

A hub, also known as a repeater, is a simple device used for years to connect all nodes, or computers, on a network to a central location. Each node on a network has a unique hardware address called a MAC address. A hub is known as a repeater because when a packet of data, or frame, is sent through the hub, it is repeated to each and every computer on the network.

A switch-based network is one that utilizes switches instead of hubs. A switch is a major upgrade to a hub. Instead of sending all network data to each and every network node, the switch will analyze the MAC address and determine where to send the data. Network bandwidth is not wasted by sending every frame to every port.

Routers not only provide connections to the internet, they also protect the LAN from the Internet. The router could block any Packet that has a destination address outside of the LAN. In short, a router can perform many of the same functions as switches and hubs, but it has address translation and filtering capabilities.

Quick description - How does a Router work?

Here is a technical description of how a router works. This would make sense if you have already an understanding of the network protocols.
The layers 2 and 3 of the OSI model i.e. Data Link layer, is where the Ethernet protocol, MAC addresses and switches fit in.
Layer 3, the Network layer, is where the IP protocol, IP addresses and routers fit in. All traffic is sent from your computer, starting with Layer 7 (your network application) and going down to Layer 1 (physical). With the physical layer, the traffic is going across your network medium.
Traffic goes to a router only if it is not on your local LAN. Routers work primarily at Layer 3 but must understand Layers 1-3, at a minimum. Many routers understand traffic all the way up to Layers 4-7 in varying ways.
One of the tools a router uses to decide where a packet should go is a configuration table. A configuration table is a collection of information, including:
• Information on which connections lead to particular groups of addresses
• Priorities for connections to be used
• Rules for handling both routine and special cases of traffic
Internet data, whether in the form of a Web page, a downloaded file or an e-mail message, travels over a system known as a packet-switching network. In this system, the data in a message or file is broken up into packages about 1,500 bytes long which includes information on the sender's address, the receiver's address, the package's place in the entire message, and how the receiving computer can be sure that the package arrived intact. Each data package, called a packet, is then sent off to its destination via the best available route -- a route that might be taken by all the other packets in the message or by none of the other packets in the message.

Introduction to Routers

A computer networking device which forwards data packets across a network toward their destinations, through a process of routing is known as Router. In companies and large corporations, a central computer system acts as a router to connect all of the company's computers to one network. This allows group participation and collaboration on large projects or just to connect all of the company's resources at one central location. It also aids in reliable communication between employees working on different floors in the building or in different countries.

1. Router is required to connect multiple networks, like your LAN to the Internet.
2. Routers store large tables of networks and addresses, then using algorithms to determine the shortest routes to individual addresses within those networks.
3. Routers not only facilitate intra-network communications, but also play a role in overall network performance.
4. Routers help in delivering the information faster.
5. Routers also protect LAN from Internet.
6. Router blocks any packet that has a destination address outside of the LAN. If the destination address is valid, the router could check the Packet for an error. If there is an error, the router could discard the Packet and send a message to the originating address.
7. Routers have address translation and filtering capabilities.

eXplore the eWorld!

In the world of computers we encounter a lot of words starting with 'e' which means electronic and it refers to the digital representation of the content.
Lets have a look at some of these eWords, and try to understand them in a very easy way...

e-paper - its a portable, reusable storage and display medium that can be repeatedly written on (i.e. refreshed) - millions of time.
Information to be displayed is downloaded through a connection to a computer or a cell phone.
epaper is used for applications such as ebooks, electronic newspapers, portable signs and foldable, rollable displays.

ebrochure - its like the brochure which explains the reader about the product, company etc, but the difference here is that ebrochure is a digital presentation style that consists of bullets, images, animations, graphics to inform the viewer (reader) about the product, company or service.

ebook - this is an electronic book which consists of variety of content that is published in a format that is small in size, portable and at the same time have all the features of a print version plus even there is an option of text being converted to speech.

eLibrary - its a virtual library that stores and delivers content that is exclusive, collection of articles, reports, features and tools. It can be seen as a personal online research centre. Its available for online reading or downloading.

e-form - a digital representation of a paper form. eforms can be filled out easily and even faster. It can automatically format, calculate, look up, and validate information for the user. And all this possible due to the programming associated with them. With electronic submission of completed forms one not only saves time but also eliminates the cost of errors.

e-outsourcing - term used for a business, where buying information technology products and services that could be furnished in-house from one or variety of sources on the internet.

e-services - these are electronic services which are very fast services. And they perform work, achieve tasks, or complete transactions where many business services can be provided for a business or consumer using the Web.

Refactoring - Code improvement without changing behavior

Refactoring is the process of changing a software system in such a way that it does not alter the external behaviour of the code/design, yet improves its internal structure. When the software is refactored, the existing design is examined for redundancy, unused design elements, inefficient or unnecessary algorithms, poorly constructed or inappropriate data structures, or any other design failure; once this inspection is done, then the results are analysed for getting a more improved design.
If you were to ask for a simple explanation, then code refactoring means that you 'clean up' the code. Refactoring is not meant to be used for changes where you added new functionality, or fixed bugs, or something similar. It is in principle used for analysing code to remove dead code, to make the code more understandable, and modify the internal structure and design (maybe to make the code more elegant, as well as to follow some standard code processes and layouts).
Why do refactoring ? The process intends to make code easier to read and comprehend, and also to be able to make modifications to it. Given the amount of time that code remains in-use, and with the people handling the code not remaining constant, it is important that the code be easy to understand and maintain. Sometimes people take on the task of improving the code in order to fix defects or solve other design issues, but that is not refactoring.
A common method used within refactoring is to change the definition of variables, such as when a non-meaning variable such as 'j' is instead changed to actually be closer to the real use of the variable, say 'ItemWeight'. This makes it easier for somebody else to quickly read the code and comprehend. This however, has its own set of complications since the same variable may be used in many different parts of the application, and the person making the modification may need to study each usage before making the change.