Wireless Speakers - Priya dharshini , III B.Tech IT B

WIRELESS SPEAKERS

 

Wireless speakers are very similar to traditional (wired) loudspeakers, but they transmit audio signals using radio frequency (RF) waves rather than over audio cables.

Wireless speakers are composed of two units: a main speaker unit combining the loudspeaker itself with an RF receiver, and an RF transmitter unit. The transmitter connects to the audio output of any audio devices such as hi-fi equipment, televisions, computers, mp3 players, etc. An RCA plug is normally used to achieve this. The receiver is positioned where the listener wants the sound to be, providing the freedom to move the wireless speakers around without the need of using cables. The receiver/speaker unit generally contains an amplifier to boost the audio signal to the loudspeaker; it is powered either by batteries or by an AC electric outlet. Batteries may last for three to four hours; some wireless speakers operate on rechargeable batteries.

The signal frequency range used by wireless speakers is generally the same as that used by cordless telephones — 900 MHz. The RF signal can traverse walls and floors/ceilings. Most manufacturers claim the signal transmits over a range of 150 to 300 feet. Many wireless speakers feature variable transmission frequencies (channels) that can be set using a tuning knob to overcome potential RF interference with other nearby wireless devices such as cordless phones or baby monitors.

Different types of wireless speakers are designed for specific needs:

 Stereo speakers can deliver both Left and Right stereo channels in a single speaker. Speakers designed specifically for outdoor use have a robust casing; manufacturers claim these are weatherproof. Home theaters utilize a specialized set of speakers in which only the rear speaker/s are wireless, while the front speakers are wired.

Wireless speakers receive considerable criticism from high-end audiophiles because of the potential for RF interference with other signal sources like cordless phones as well as for the relatively low sound quality some models deliver. Despite the criticism, wireless speakers have gained popularity with consumers and a growing number of models are actively marketed.

Plastic Memory - Karthiga S P, III B.Tech IT A

PLASTIC MEMORY

A conducting plastic has been used to create a new memory technology with the potential to store a megabit of data in a millimeter-square device - 10 times denser than current magnetic memories. The device should also be cheap and fast, but cannot be rewritten, so would only be suitable for permanent storage.

The device sandwiches a blob of a conducting polymer called PEDOT and a silicon diode between two perpendicular wires. Substantial research effort has focused on polymer-based transistors, which could form cheap, flexible circuits, but polymer-based memory has received relatively little attention.

The key to the new technology was the discovery by researchers from Princeton University, New Jersey, and Hewlett-Packard Laboratories in Palo Alto, California, that passing a high current through PEDOT turns it into an insulator, rather like blowing a fuse. The polymers two possible states, conductor or insulator, then form the one and zero necessary to store digital data.

"The beauty of the device is that it combines the best of silicon technology - diodes - with the capability to form a fuse, which does not exist in silicon," says Vladimir Bulovic, who works on organic electronics at the Massachusetts Institute of Technology.

However, turning the polymer INTO an insulator involves a permanent chemical change, meaning the memory can only be written to once. Its creators say this makes it ideal for archiving images and other data directly from a digital camera, cell phone or PDA, like an electronic version of film negatives.

Ion snatch:

PEDOT's ability to conduct electricity means it is already used widely as the anti-static coating on camera film. But until now, no one suspected that it could be converted into an insulator.

The material is a blend of a negatively-charged polymer called PSS- and a positively-charged one called PEDT+. Having distinct, charged components allows it to conduct electricity and means that it is water soluble.

The team is not sure why it stops conducting when high currents pass through. But Princeton researcher Stephen Forrest suspects that the heat produced by a high current gives the PSS- layer sufficient energy to snatch a positively-charged hydrogen ion from any water that has dissolved on its surface, forming a neutral PSSH.

Without the negatively-charged PSS- to stabilize it, PED+ in turn grabs on to an extra electron and also becomes neutral, converting PEDOT into an insulating polymer.

Read and write:

To store the memory, the researchers use the wires and the diode surrounding the PEDOT blob to run either a high or a low current through it. This either creates an insulator or leaves it as a conductor.

To read the memory, they run current through the top wire and measure the current in the bottom wire. No current means the bit is a zero, and vice versa.

In their paper in Nature, the researchers describe just one such junction. But for a memory application, the device will need many more. So the Hewlett-Packard team is now working on building a grid of intersecting wires. In this way, they can read and write multiple bits to one device. A grid system is commonly used in display screens to switch individual pixels.

Polymer devices can spray or printed, and are therefore much cheaper than silicon devices, which must be etched.

Cheap, Plastic Memory for Flexible Devices

Cheap and plastic aren't words often associated with cutting-edge technology. But researchers in Tokyo have created a new kind of plastic low-cost flash memory that could find its way into novel flexible electronics.

Flash memory stores data electrically, in specially designed silicon transistors. Information can be recorded and read quickly and is retained even when the power is off. This makes flash ideal for MP3 players, cameras, memory cards, and USB drives. But the technology is still more expensive than conventional hard disks.

The prototype plastic flash memory cannot match silicon's storage density, long-term stability, or number of rewrite cycles. But its low cost could make it possible to integrate flash memory into more unconventional electronics. For example, cheap plastic memory devices might be incorporated into e-paper or disposable sensor tags.

APPLICATIONS:

Memory Expanding Flechettes

Memory Expanding Flechettes (more commonly known as Expanders) borrow bleeding-edge technology from the famous Spawn Blades and adapts it to firearms use. Each flechette in the cluster expands and compresses (thanks to memory plastics) to roughly the shape and size of a quarter once inside a soft target. They penetrate armor as well as most flechettes (1/2 SP), but do terrifying damage once beyond it (increase penetrating damage by 50%). Due to the multiple hits, armor penetrated is reduced 3 levels.

BallisTech Skintight Mark III:

 

Skintight body armor was first introduced for police use in 2013. At the time it was a remarkable piece of Memory Plastic technology that made claims it couldn't hold up to. The 2021 edition (mark III) is finally a body armor people are looking at again. Not incredibly useful on its own, it is at it's best under another layer of armor. Treat Skintight as being SP40, but any damage up to that 40 mark is no prevented, it is only reduced by 1/3 as the thin layer of memory plastic attempts to redirect the kinetic energy across the material instead of through it. Damage over the 40 mark is dealt in full (with AP rounds of course reducing this to 20). Any time the armor is penetrated, reduce this threshold by 5SP. directly after the impact, the suit is stiff and hard from the memory plastics redirecting the impact energy, and the suit gains an EV of 1. If the suit collects more than 3 hits in one round it becomes EV 2 as it stiffens even further. The EV is reduced by 1 point at the beginning of every round as the suit softens again. The suit covers the full body except the head, hands and feet. 

Geographical Information System - Dhara P, Archana T, III B.Tech IT A

GEOGRAPHICAL INFORMATION SYSTEM

Abstract- Most of the discussion of time in GIS fits into the general topic of developing a useful model of geographic data. Data models, at their most abstract level, describe objects, relationships, and a system of constraints or axioms. So far, most GIS research posits universal axioms with a strong geometric basis. Time is usually spatialized. Models of GIS should develop to include more than the data, since an operating GIS must be connected to its context in social, economic and administrative life. While time might be reasonably represented as an axis in data space, as a technology, GIS develops in a complex, multi-thread system of events. Understanding the historical nature of the participants in the GIS can help sort out the diversity of data models and the inability to develop common understandings.

 

KEY WORDS: GIS, Raster, Cartography, Spatial.

 

I.INTRODUCTION

 

A Geographic Information System is also called as Geographical Information System or Geospatial Information System. It is a system   designed to capture, store, manipulate, analyze, manage and present all types of geographically referenced data. In simple terms GIS is called as the merging of Cartography.GIS describes any information system that integrates, stores, edits, analyzes, shares and displays geographic information for informing decision making. Modern GIS technologies use digital information, for which various digitized data creation methods are used. Land Surveyors have been able to provide a high level of positional accuracy utilizing the GPS derived positions. A GIS can also convert existing digital information, which may not yet be in map form, into forms it can recognize, employ for its data analysis processes, and use in forming mapping output. Map information in a GIS must be manipulated so that it registers, or fits, with information gathered from other maps.

 

II.GIS TECHNIQUES

 

The most common method of data creation is digitization, where a hard copy map or survey plan is transferred into a digital medium through the use of a computer-aided design (CAD) program, and geo-referencing capabilities. With the wide availability of ortho-rectified imagery. Heads-up digitizing is becoming the main avenue through which geographic data is extracted. Heads-up digitizing involves the tracing of geographic data directly on top of the aerial imagery instead of by the traditional method of tracing the geographic form on a separate digitizing tablet. The key characteristic of GIS has begun to open new avenues of scientific inquiry into behaviors and patterns of previously considered unrelated real-    world information.

 

III.GIS REPRESENTATION

 

GIS data represents real objects (such as roads, land use, elevation, etc.) with digital data determining the mix. Real objects can be divided into two abstractions: Discrete objects  and Continuous fields.Traditionally, there are two broad methods used to store data in a GIS for both kinds of abstractions mapping references: Raster images and Vector. Points, lines, and polygons are the stuff of mapped location attribute references. A raster data type is, in essence, anytype of digital image represented by reducible and enlargeable grids. Anyone who is familiar with digital photography will recognize the Raster graphics pixel as the smallest individual grid unit building block of an image, usually not readily identified as an artifact shape until an image is produced on a very large scale. Raster data can be images with each pixel containing a color value. In a GIS, geographical features are often expressed as vectors, by considering those features as geometrical shapes. A simple vector map, using each of the vector elements: points, lines, and polygons. No measurements are possible with point features. Line features can measure distance. Polygon features can measure perimeter and area. Vector data can also be used to represent continuously varying phenomena. Additional non-spatial data can also be stored along with the spatial data represented by the coordinates of a  vector geometry or the position of a raster cell. In vector data, the additional data contains attributes of the feature. Raster data is stored in various formats; from a standard file-based structure of TIF, JPEG, etc. to binary large object (BLOB) data stored directly in a relational database management system (RDBMS) similar to other vector-based feature classes. Database storage, when properly indexed, typically allows for quicker retrieval of the raster data but can require storage of millions of significantly sized records.Vector features can be made to respect spatial integrity through the application of topology rules such as 'polygons must not overlap'.

 

IV. MODELING IN GIS

 

There are many types of modeling in GIS. Some of them are discussed below.

 

DATA MODELING:

 

 A GIS, however, can be used to depict two- and three-dimensional characteristics of the Earth's surface, subsurface, and atmosphere from information points. Many sophisticated methods can estimate the characteristics of surfaces from a limited number of point measurements. A two-dimensional contour map created from the surface modeling of rainfall point measurements may be overlaid and analyzed with any other map in a GIS covering the same area. Watersheds can be easily defined for any given reach, by computing all of the areas contiguous and uphill from any given point of interest. Similarly, an expected thalweg of where surface water would want to travel in intermittent and permanent streams can be computed from elevation data in the GIS.

TOPOLOGICAL MODELING:

A GIS can recognize and analyze the spatial relationships that exist within digitally stored spatial data. These topological relationships allow complex spatial modeling and analysis to be performed. Topological relationships between geometric entities traditionally include adjacency (what adjoins what), containment (what encloses what), and proximity (how close something is to something else).

HYDROLOGICAL MODELLING:

GIS hydrological models can provide a spatial element that other hydrological models lack, with the analysis of variables such as slope, aspect and watershed or catchment area. Terrain analysis is fundamental to hydrology, since water always flows down a slope.

CARTOGRAPHIC MODELING:

The term "cartographic modeling" was  coined by Dana Tomlin in his PhD dissertation and later in his book which has the term in the title. Cartographic modeling refers to a process where several thematic layers of the same area are produced, processed, and analyzed. Tomlin used raster layers, but the overlay method can be used more generally. Operations on map layers can be combined into algorithms, and eventually into simulation or optimization models.

(An  example of use of layers in a GIS application.In this example,the forest cover layer(light green)is at the bottom with a topographic layer over it.Next up is the stream layer,then the boundary laywr,then the road layer.The order is very important in order to properly display the final result.Note that the pond layer was located just below the stream layer,

MAP OVERLAY:

The combination of several spatial datasets  creates a new output vector dataset, visually similar to stacking several maps of the same region. These overlays are similar to mathematical Venn diagram overlays. A union overlay combines the geographic features and attribute tables of both inputs into a single new output. An intersect overlay defines the area where both inputs overlap and retains a set of attribute fields for each. A symmetric difference overlay defines an output area that includes the total area of both inputs except for the overlapping area.Data extraction is a GIS process similar to vector overlay, though it can be used in either vector or raster data analysis.

 

V. DATA OUTPUT AND CARTOGRAPHY

Cartography is the design and production of maps, or visual representations of spatial data. The vast majority of modern cartography is done with the help of computers, usually using a GIS but production quality cartography is also achieved by importing layers into a design program to refine it. Most GIS software gives the user substantial control over the appearance of the data. Cartographic work serves two major functions:First, it produces graphics on the screen or on paper that convey the results of analysis to the people who make decisions about resources. Wall maps and other graphics can be generated, allowing the viewer to visualize and thereby understand the results of analyses or simulations of potential events. Second, other database information can be generated for further analysis or use.

 

VI. GRAPHIC DISPLAY TECHNIQUES

Traditional maps are abstractions of the real world, a sampling of important elements portrayed on a sheet of paper with symbols to represent physical objects. People who use maps must interpret these symbols. Topographic maps show the shape of land surface with contour lines or with shaded relief.Today, graphic display techniques such as shading based on altitude in a GIS can make relationships among map elements visible, heightening one's ability to extract and analyze information. For example, two types of data were combined in a GIS to produce a perspective view of a portion of San Mateo County, California.

·       The digital elevation model, consisting of surface elevations recorded on a 30-meter horizontal grid, shows high elevations as white and low elevation as black.

·       The accompanying Landsat Thematic Mapper image shows a false-color infrared image looking down at the same area in 30-meter pixels, or picture elements, for the same coordinate points, pixel by pixel.                   

A GIS was used to register and combine the two images to render the three-dimensional perspective view looking down the San Andreas Fault, using the Thematic Mapper image pixels, but shaded using the elevation of the landforms. The GIS display depends on the viewing point of the observer and time of day of the display, to properly render the shadows created by the sun's rays at that latitude, longitude, and time of day.An archeochrome is a new way of displaying spatial data. It is a thematic on a 3D map that is applied to a specific building or a part of a building. It is suited to the visual display of heat loss data.

VII.GIS DEVELOPMENTS

Many disciplines can benefit from GIS technology. An active GIS market has resulted in lower costs and continual improvements in the hardware and software components of GIS. These developments will, in turn, result in a much wider use of the technology throughout science, government, business, and industry, with applications including real estate, public health, crime mapping, sustainable development, natural resources, landscape architecture, archaeology, regional and community planning, transportation and logistics. GIS is also diverging into location-based services (LBS). LBS allows GPS enabled mobile devices to display their location in relation to fixed assets (nearest restaurant, gas station, fire hydrant), mobile assets (friends, children, police car) or to relay their position back to a central server for display or other processing. These services continue to develop with the increased integration of GPS functionality with increasingly powerful mobile electronics (cell phones, PDAs, laptops).GIS technology, as an expansion of cartographic science, has enhanced the efficiency and analytic power of traditional mapping. Now, as the scientific community recognizes the environmental consequences of anthropogenic activities influencing climate change, GIS technology is becoming an essential tool to understand the impacts of this change over time. GIS enables the combination of various sources of data with existing maps and up-to-date information from earth observation satellites along with the outputs of climate change models. This can help in understanding the effects of climate change on complex natural systems. The outputs from a GIS in the form of maps combined with satellite imagery allow researchers to view their subjects in ways that literally never have been seen before.

VIII.ADVANTAGES AND DISADVANTAGES

There are some important advantages and disadvantages to using a raster or vector data model to represent reality:

·       Raster datasets record a value for all points in the area covered which may require more storage space than representing data in a vector format that can store data only where needed.

·       Raster data allows easy implementation of overlay operations, which are more difficult with vector data.

·       Vector data can be displayed as vector graphics used on traditional maps, whereas raster data will appear as an image that may have a blocky appearance for object boundaries. (depending on the resolution of the raster file)

·       Vector data can be easier to register, scale, and re-project, which can simplify combining vector layers from different sources.

·       Vector data is more compatible with relational database environments, where they can be part of a relational table as a normal column and processed using a multitude of operators.

·       Vector file sizes are usually smaller than raster data, which can be tens, hundreds or more times larger than vector data (depending on resolution).

·       Vector data is simpler to update and maintain, whereas a raster image will have to be completely reproduced. (Example: a new road is added).

·       Vector data allows much more analysis capability, especially for "networks" such as roads, power, rail, telecommunications, etc. (Examples: Best route, largest port, airfields connected to two-lane highways). Raster data will not have all the characteristics of the features it displays.

IX. APPLICATIONS

GIS technology can be used for:

·       earth surface-based scientific investigations

·       resource management

·       reference and projections of a geospatial nature, both man-made and natural

·       asset management and location planning

·       archaeology

·       environmental impact-assessment

·       infrastructure assessment and development

X. CONCLUSION

Model of GIS cannot treat time as a sterile, abstract dimension without losing the historical specificity of its context. Modeling of GIS must extend beyond the data stored in the GIS to include the institutions that adopt the technology and the conversions of the industry that manages spatial information. Once these components are included, a model of time must include specific events and historical processes that lead to meanings of geographic phenomena amongst the diverse participants. The field of GIS is beset by cultural expectations about time and progress. These cloud the importance of historical context in the implementation and development of these technological changes. Research in GIS should not stop with models of the data inside the GIS. The technological development process itself has historical roots and progresses in paths not entirely picked for the purest reasons. Even more importantly, the meaning of that data comes from the users and from the context of the uses. The context in turn is heavily influenced by the historical processes that lead to this point. A multi-thread model of historical origins seems much more appropriate than the single axis models that pervade the current thinking. 

RAIN TECHNOLOGY - Palaniyappan M, II B.Tech IT

What is Rain Technology?

The name of the original research project was RAIN, which stands for Reliable Array of Independent Nodes. Rain finity's technology originated in a research project at the California Institute of Technology (Caltech) in collaboration with NASA's Jet Propulsion Laboratory and the Defense Advanced Research Projects Agency (DARPA). The goal of the RAIN project was to identify key software building blocks for creating reliable distributed applications using off-the-shelf hardware. The focus of the research was on high-performance, fault-tolerant and portable clustering technology for space-borne computing.

In short, the RAIN project intended to marry distributed computing with networking protocols. During the RAIN project, key components were built to fulfill this vision. A patent was filed and granted for the RAIN technology. It became obvious that RAIN technology was well-suited for Internet applications. Rainfinity was spun off from Caltech in 1998, and the company has exclusive intellectual property rights to the RAIN technology. After the formation of the company, the RAIN technology has been further augmented, and additional patents have been filed.

RAIN is also called channel bonding, redundant array of independent nodes, reliable array of independent nodes, or random array of independent nodes. It is a cluster of nodes linked in a network topology with multiple interfaces and redundant storage. It is an implementation of RAID across nodes instead of across disk arrays. RAIN is used to increase fault tolerance.

ORIGIN

Rain Technology developed by the California Institute of technology ,in collaboration with NASA's Jet Propulsion

1. laboratory and the DARPA.
2. The name of the original research project was RAIN, which stands for Reliable Array of Independent Nodes.
3. The RAIN research team in 1998formed a company called Rainfinity.

FEATURES OF RAIN

• It includes scalability and high availability.
• Many novel features in an attempt to deal with faults in nodes, network, and data storage.
  Bundled interfaces
  Link monitoring
  Fault tolerant interconnect
• Group members
• Data storage

ADVANTAGES

• RAIN Technology is the most scalable software cluster technology for the Internet marketplace today.
• There is no limit on the size of a RAIN cluster.
• All nodes are active and can participate in load balancing.

This software only technology is open and highly portable.

RAIN (redundant/reliable array of inexpensive/independent nodes)

RAIN (also called channel bonding, redundant array of independent nodes, reliable array of independent nodes, or random array of independent nodes) is a cluster of nodes connected in a network topology with multiple interfaces and redundant storage. RAIN is used to increase fault tolerance. It is an implementation of RAID across nodes instead of across disk arrays.

RAIN can provide fully automated data recovery in a local area network (LAN) or wide area network (WAN) even if multiple nodes fail. A browser-based, centralized, secure management interface facilitates monitoring and configuration from a single location. There is no limit to the number of nodes RAIN cluster. New nodes can be added, and maintenance conducted, without incurring network downtime.

RAIN originated in a research project for computing in outer space at the California Institute of Technology (Caltech), the Jet Propulsion Laboratory (JPL), and the Defense Advanced Research Projects Agency (DARPA) in the United States. The researchers were looking at distributed computing models for data storage that could be built using off-the-shelf components.

The idea for RAIN came from RAID (redundant array of independent disks) technology. RAID partitions data among a set of hard drives in a single system. RAIN partitions storage space across multiple nodes in a network. Partioning of storage is called disk striping. Several patents have been granted for various proprietary versions of RAIN.

Rainfinity's technology originated in a research project at the California Institute of Technology (Caltech), in collaboration with NASA's Jet Propulsion Laboratory and the Defense Advanced Research Projects Agency (DARPA). The name of the original research project was RAIN, which stands for Reliable Array of Independent Nodes. The goal of the RAIN project was to identify key software building blocks for creating reliable distributed applications using off-the-shelf hardware. The focus of the research was on high-performance, fault-tolerant and portable clustering technology for space-borne computing. Two important assumptions were made, and these two assumptions reflect the differentiations between RAIN and a number of existing solutions both in the industry and in academia:

1) The most general share-nothing model is assumed. There is no shared storage accessible from all computing nodes. The only way for the computing nodes to share state is to communicate via a network. This differentiates RAIN technology from existing back-end server clustering solutions such as SUNcluster, HP MC Serviceguard or Microsoft Cluster Server.

2) The distributed application is not an isolated system. The distributed protocols interact closely with existing networking protocols so that a RAIN cluster is able to interact with the environment.Specifically, technological modules were created to handle high-volume network-based transactions.

In short, the RAIN project intended to marry distributed computing with networking protocols. It became obvious that RAIN technology was well-suited for Internet applications. During the RAIN project,

components were built to fulfill this vision. A patent was filed and granted for the RAIN technology. Rainfinity was spun off from Caltech in 1998, and the company has exclusive intellectual property rights to the RAIN technology. After the formation of the company, the RAIN technology has been further augmented and additional patents have been filed.

"Its Architecture"

The RAIN technology incorporates a number of unique innovations as its core modules:

Reliable transport ensures the reliable communication between the nodes in the cluster. This transport has a built-in acknowledgement scheme that ensures reliable packet delivery. It transparently uses all available network links to reach the destination. When it fails to do so, it alerts the upper layer, therefore functioning as a failure detector. This module is portable to different computer platforms, operating systems and networking environments.
Consistent global state sharing protocol provides consistent group membership, optimized information distribution and distributed group-decision making for a RAIN cluster. This module is at the core of a RAIN cluster. . It enables efficient group communication among the computing nodes, and ensures that they operate together without conflict.

Always-On-IP maintains pools of "always-available" virtual IPs. These virtual IPs are logical addresses that can move from one node to another for load sharing or fail-over. Usually a pool of virtual IPs is created for each subnet that the RAIN cluster is connected to. A pool can consist of one or more virtual IPs. Always-On-IP guarantees that all virtual IP addresses representing the cluster are available as long as at least one node in the cluster is operational. In other words, when a physical node fails in the cluster, its virtual IP will be taken over by another healthy node in the cluster.

Local and global fault monitors track on a continuous or event-driven basis, the critical resources within and around the cluster: network connections, Rainfinity or other applications residing on the nodes, remote nodes or applications. They are an integral part of the RAIN technology, guaranteeing the healthy operation of the cluster.
Secure and central management offers a browser-based management GUI for centralized monitoring and configuration of all nodes in the RAIN clusters.The central management GUI connects to any node in the cluster to obtain a single-system view of the entire cluster. It actively monitors the status, and can send operation and configuration commands to the entire cluster.

"Benefits"

RAIN technology is the most scalable software cluster technology for the Internet marketplace today. There is no limit to the size or the performance of a RAIN cluster. Within a RAIN cluster, there is no master-slave relationship or primary-secondary pairing. All nodes are active and can participate in load balancing. Any node can fail-over to any other node. A RAIN cluster can tolerate multiple node failures, as long as at least one node is healthy. It employs highly efficient consistent state sharing and decision making protocols, so that the entire cluster can function as one system.

A RAIN cluster is a true distributed computing system that is resilient to faults.It behaves well in the presence of node, link and application failures, as well as transient failures. When there are failures in the system, a RAIN cluster gracefully degrades its performance to exclude the failed node, but maintains the overall functionality. New nodes can be added into the cluster "on the fly" to participate in load sharing, without taking down the cluster. With RAIN, online maintenance without downtime is possible. Part of the cluster can be taken down for maintenance, while the other part maintains the functionality.


This software-only technology is open and highly portable. It works with a variety of hardware and software environments. Currently it has been ported to Solaris, NT and Linux.It is conceivable to port it to more environments, including embedded systems. It supports a heterogenous environment as well, where the cluster can consist of nodes of different operating systems with different configurations. There is no distance limitation to RAIN technology. It supports clusters of geographically distributed nodes. It can work with many different Internet applications.

Guiding concepts that shaped the architecture of RAIN technology are as follows:

• Network Applications:

The architecture goals for clustering data network applications are different from clustering data storage applications. Similar goals apply in the telecom environment that provides the Internet backbone infrastructure, due to the nature of applications and services being clustered.

• Shared-Nothing

The shared-storage cluster is the most widely used for database and application servers that store persistent data on disks. This type of cluster typically focuses on the availability of the database or application service, rather than performance. Recovery from failover is generally slow, because restoring application access to disk-based data takes minutes or longer, not seconds. Telecom servers deployed at the edge of the network are often diskless, keeping data in memory for performance reasons, and tolerate low failover time. Therefore, a new type of share-nothing cluster with rapid failure detection and recovery is required. The only way for the shared-nothing cluster to share is to communicate via the network.

• Scalability

While the high-availability cluster focuses on recovery from unplanned and planned downtimes, this new type of cluster must also be able to maximize I/O performance by load balancing across multiple computing nodes. Linear scalability with network throughput is important. In order to maximize the total throughput, load load-balancing decisions must be made dynamically by measuring the current capacity of each computing node in real-time. Static hashing does not guarantee an even distribution of traffic.

• Peer-to-Peer

A dispatcher-based, master-slave cluster architecture suffers from scalability by introducing a potential bottleneck. A peer-to-peer cluster architecture is more suitable for latency-sensitive data network applications processing shortlived sessions. Hybrid architecture should be considered to offset the need for more control over resource management. For example, a cluster can assign multiple authoritative computing nodes that process traffic in the round-robin order for each network interface that is clustered to reduce the overhead of traffic forwarding.

RAIN (also called channel bonding, redundant array of independent nodes, reliable array of independent nodes, or random array of independent nodes) is a cluster of nodes connected in a network topology with multiple interfaces and redundant storage. RAIN is used to increase fault tolerance. It is an implementation of RAID across nodes instead of across disk arrays.
RAIN can provide fully automated data recovery in a local area network (LAN) or wide area network (WAN) even if multiple nodes fail. A browser-based, centralized, secure management interface facilitates monitoring and configuration from a single location. There is no limit to the number of nodes that can exist in a RAIN cluster. New nodes can be added, and maintenance conducted, without incurring network downtime.

Universal Serial Bus 3.0 - Shyam Sunder R, III B.Tech IT 'B'

Introduction:-

USB 3.0 is the third major revision of the Universal Serial Bus (USB) standard for computer connectivity. USB 3.0 has transmission speeds of up to 5 GB/s, which is 10 times faster than USB2.0 (480 MB/s). USB 3.0 significantly reduces the time required for data transmission, reduces power consumption, and is downward compatible with USB 2.0. The USB 3.0 Promoter Group announced on 17 November 2008 that the specification of version 3.0 had been completed and had made the transition to the USB implementers forum (USB-IF) the managing body of USB specifications. This move effectively opened the specification to hardware developers for implementation in future products.

The first USB 3.0 consumer products were announced and shipped by BUFFALO TECHNOLOGY in November 2009, while the first certified USB 3.0 consumer products were announced 5 January 2010, at the Las Vegas CONSUMERS ELECTRONICS SHOW (CES) including two motherboards by ASUS and Gigabyte Technologies.

Manufacturers of USB 3.0 host controllers include, but are not limited to,RENASAS Electronic, Fresco Logic, As media, Etron VIA Technoloies,TEXAS Instruments and NVIDIA of November 2010, Renesas is the only company to have passed USB-IF certification, although motherboards for Intel’s  sandy bridge  processors have been seen with As media and Etron host controllers. On October 28, 2010 HEWLETT PACKWARD released the HP Envy 17 3D featuring a Renesas USB 3.0 Host Controller several months before some of their competitors. AMD is working with Renesas to add its USB 3.0 implementation into its chipsets for its 2011 platforms. 

 

Features:-

A new feature is the "Super Speed" bus, which provides a fourth transfer mode at 5.0 GB/s. The raw throughput is 4 GB/s, and the specification considers it reasonable to achieve 3.2 GB/s (0.4 GB/s or 400 MB/s), or more, after protocol overhead. In order to achieve increased data throughput, USB 3.0 introduces an additional two differential pairs over ‘FULL DUPLEX’ which signaling occurs. This results in a USB 3.0 cable having a total of 8 wires: one power, one ground, two for non-Super Speed data (as one differential pair), four wires for Super Speed data (as two differential pairs), and a shield that was not required in previous specifications. To accommodate the additional pins for Super Speed mode, the physical form factors for USB 3.0 plugs and receptacles have been modified. Standard-A plugs have been extended in length (accordingly the port is deeper) with the Super Speed pins extending beyond the legacy pins. Super Speed Standard-B plugs  have the Super Speed pins placed on top of the existing form factor.

 

To ensure backward compatibility (limited to legacy modes):

• A legacy Standard-A plug will fit a Super Speed Standard-A port;
• A legacy Standard-B plug will fit a Super Speed Standard-B port;
• A Super Speed Standard-A plug will fit a legacy Standard-A port;

Super Speed establishes a communications pipe between the host and each device, in a host-directed protocol. In contrast, USB 2.0 broadcasts packet traffic to all devices.

USB 3.0 extends the bulk transfer type in Super Speed with Streams. This extension allows a host and device to create and transfer multiple streams of data through a single bulk pipe.

New power management features include support of idle, sleep and suspend states, as well as link-, device-, and function-level power management.

The bus power spec has been increased so that a unit load is 150 MA (+50% over minimum using USB 2.0). An un-configured device can still draw only one unit load, but a configured device can draw up to six unit loads (900 MA, an 80% increase over USB 2.0 at a registered maximum of 500 MA). Minimum device operating voltage is dropped from 4.4 V to 4.0 V.

USB 3.0 does not define cable assembly lengths, except that it can be of any length as long as it meets all the requirements defined in the specification. Although electronicdesign.com estimated cables will be limited to 3 m at Super Speed, cables which support Super Speed are already available up to 5 m long.

The technology is similar to a single channel (1×) of PCI Express 2.0(5GB/s), It uses 8B/10B encoding, Linear Feed Back Shift Register (LFSR) scrambling for data and Spread Spectrum. It forces receivers to use low frequency periodic signaling (LFPS), dynamic equalization, and training sequences to ensure fast signal locking.

Availability:-

USB 3.0 support can be added to existing laptop computers with only USB 2.0 and Express card support by using an Express card-to-USB 3.0 adapter to supply USB 3.0 signal support. The Express card cannot itself deliver power, which must be derived from a USB 2.0 ports or an external power supply. Possibilities, depending upon connectors on devices, include:

• Some Expresscard-to-USB 3.0 adapters can be connected by a cable to a USB 2.0 port on the computer, which supplies power
• A cable plugs into the drive and has two USB connectors, one to the USB 3.0 port (signal) and one to a USB 2.0 port (power).
• If the external device has an appropriate connector, it can be powered by an External Power Supply.

Speed issues:-

There have been many reports of USB 3.0 equipment only transferring data at USB 2.0 speed, usually with a message "This USB Mass Storage Device can transfer information faster if you connect it to a Super-Speed USB 3.0 port". This has been due to several causes, including drivers, certain cables specified as USB 3.0 (problems disappeared when a different cable was used), order of starting equipment, equipment needing to be disconnected and reconnected, and overclocked computers.

 

PINOUTS:-

 

USB 3.0 pinouts
Pin	Color	Signal name ('A' connector)	Signal name ('B' connector)
1	Red	VBUS
2	White	D−
3	Green	D+
4	Black	GND
5	Blue	StdA_SSRX−	StdA_SSTX−
6	Yellow	StdA_SSRX+	StdA_SSTX+
7	Shield	GND_DRAIN
8	Purple	StdA_SSTX−	StdA_SSRX−
9	Orange	StdA_SSTX+	StdA_SSRX+
Shell	Shell	Shield

 

USB 2.0 vs. USB 3.0:-

The beauty of USB 3.0 is its backward compatibility with USB 2.0; you need a new cable and new host adapter to achieve USB 3.0, but you can still use the device on a USB 2.0 port and achieve typical USB 2.0 performance.

The benefit here is that USB 3.0 is a powered port, so you don't need to have another external power supply running to the drive (as you do with eSATA; unless the eSATA drive you're using is designed to steal power from a USB port while transferring data over the eSATA interface).

  

Conclusion:-

While we have yet to see any device capable of defining the performance limits of USB 3.0, benchmarks prove it’s a huge step up from USB 2.0, even when using a average desktop hard drive. USB 3.0 is able to match the eSATA controller against which it initially competes, and its 5.0 Gb/s limit will continue to remain competitive, even after 6.0 Gb/s transfers are applied to eSATA.

It produces  around 50% more amperage over the same power wires as the USB 2.0 interface it shares, USB 3.0 looks to become the de-facto standard for high-speed portable devices. The marketing power of the USB name, along with its shared connector and compatibility with non-ATA devices, will likely relegate the competing eSATA standard to stationary backup devices. Asus’ solution appears to be the most elegant option because it doesn’t steal pathways from the x16 graphics card slot, but instead relies on a PLX bridge to convert four of the chipset’s 2.5 Gb/s pathways to two 5.0 Gb/s pathways. Yet Gigabyte managed to edge out Asus n write performance by taking its 5.0 Gb/s pathway directly from the CPU, eliminating any middle parts (like the DMI interface connecting Core i7 to P55) that could slow the interface down , while also limiting the PCIe slot to X8 mode.