The Bluetooth SIG and specifications Essay Example for Free

The Bluetooth SIG and specifications Essay If the success of Bluetooth is measured by its initial interest alone then its prominence has already been assured. Before products were on sale, hundreds of companies joined the Bluetooth Special Interest Group (SIG) and the Bluetooth brand became recognized worldwide. Before investigating the technology further it is appropriate to comment about the role played by the SIG, the administrative structure of which is outlined in Figure 3. With membership of the SIG nearing 2500 members it is only right to look at how the SIG works to promote, shape and define the specification and position Bluetooth in the market place. Positioning of the technology is important when you consider other wireless technologies that share the same ISM band, e.g. IEEE802.11b, HomeRF and DECT. Differentiation is key in avoiding confusion of potential users. Figure 3: Bluetooth SIG Administrative Structure In 1994, Ericsson Mobile Communications began to examine alternatives to cables linking accessories with their mobile phones. This study produced the initial specification for wireless technology, with the Bluetooth SIG founded in February 1998 by the core promoters: Ericsson Mobile Communications AB. Intel Corp. IBM Corp. Toshiba Corp. Nokia Mobile Phones. The core promoters announced the global SIG in May 1998 and invited other companies to join as Bluetooth adopters. In July 1999 the core promoters published version 1.0 of the specification and further enlarged the core promoter group in December 1998 with the inclusion of: v Microsoft v Lucent (now Agere) v 3Com. v Motorola. The responsibility for the various Bluetooth specifications is in the hands of the individual technical working groups. Once a specification reaches a version level 0.5 it is made visible to associate members. An associate members must be recommended by a promoter, and submit a fee. When a specification reaches version 1.0 it gets a higher level of visibility. Now adopters have visibility and any company can become an adopter by joining the SIG, signing and submitting the membership agreement (see â€Å"Bluetooth†). The Bluetooth specifications are open specifications for wireless communications that are free to download and use; however to use it royalty free you do have to join the SIG. By joining the group you sign up to an adopter’s agreement sharing any patents essential for implementing Bluetooth. The specifications define minimum functionality allowing devices from different companies to communicate (see â€Å"Bluetooth†). . They provide the following: o  Ã‚   Protocol definitions for interoperability o  Ã‚   Host controller interface o  Ã‚   Bearer services for higher layer protocols o  Ã‚   Profiles o  Ã‚   Qualification o  Ã‚   Production test o  Ã‚   Brand book The Bluetooth specifications define the concept of a Personal Area Network (PAN), what they do not provide helps to position it in the ISM band. It is not focussed on Wide Area Networking (WAN) as it has a limited range and currently there is no hand over mechanism, though there is a working group. They do not provide implementation instructions at the application programming interfaces, user interfaces or a definition of hardware and software split. Although it could be argued there is guidance in the profiles’ specification. The rest of this section breaks down the specifications encompassing the key aspects of Bluetooth in order to explain the features (see â€Å"Bluetooth†). A.2.1 The Protocol Stack The Bluetooth specifications define not only a radio system but cover the underlying structure. The Core Specification contains a software protocol stack similar to the more familiar Open Systems Interconnect (OSI) standard reference model for communication protocol stacks. It permits applications to discover devices, the services they offer and permission to use these services. The stack is a sequence of layers with features crossing single or multiple layered boundaries. Figure 4 outlines the stack with each block corresponding to a Core Specification chapter. Other remaining chapters relate to compliance requirements, test modes and test control interface (see â€Å"Bluetooth†). If we ascend the stack, we first come across the fundamental component, the radio. The radio modulates and demodulates data for transmitting and receiving over the air. The operating band of the radio is divided into 1 MHz spaced channels with a chosen modulation scheme of Gaussian Frequency Shift Keying (GFSK). Each channel is specified to signal at 1mega symbols per second, equivalent to 1 Mb/s. Above the radio are the Baseband and Link Controller, they are responsible for controlling the physical links via the radio, and assembling the packets and controlling the frequency hopping (see â€Å"Bluetooth†. Progressing through the layers, the Link Manager (LM) controls and configures links to other devices. The Host Controller Interface (HCI) is above the LM layer and is probably one of the most important layers to consider as a designer. It handles communication between host and the module. The standard defines the HCI command packets that the host uses to control the module, the event packets used by the host to inform lower protocol layers of changes, the data packets for voice and data traffic between host and module and the transport layer used by the HCI packets. The transport layer can be USB (H2), RS232 (H3), UART (4) or a robust proprietary standard such as BCSP (BlueCore Serial Protocol). The Logical Link Control and Adaptation (L2CAP) is a multiplexor, adapting data from higher layers and converting between different packet sizes. The next 4 layers could be loosely grouped as communication interfaces. These are RFCOMM (Radio Frequency COMMunication port) which provides an RS232 like serial interface. Wireless Application Protocol (WAP) and OBject EXchange (OBEX) are responsible for providing interfaces to other Communications Protocols. The final member of this rough grouping is the Telephony Control protocol Specification (TCS) providing telephony services. Service Discovery Protocol (SDP) lets devices discover the services available on another Bluetooth device (see â€Å"Bluetooth†). Figure 4: The Bluetooth Protocol Stack The application layer is probably obvious, but the standard provides Profiles laying out rules for how applications use the protocol stack, ensuring interoperability at application level (see â€Å"Bluetooth†).

Specialists Create Market Efficiency :: essays papers

Specialists Create Market Efficiency The NYSE should not abolish specialists. Both the NYSE and NASDAQ, however, need to realize that their relative trading volumes will continue to deteriorate as ECN's become more and more popular. The need for secondary and third markets will be diminished, however they still offer liquidity, so in some shape or form they will always be fashionable to certain types of investors. The current system established within NYSE is very old and outdated. For any single trade, a number of players must be involved. First, an investor places a buy or sell order to a broker. The brokerage firm then contacts its commission broker, who is actually on the floor, to consummate the order. In this rigid and time consuming system, the specialist plays a major part in any trade. Any buying or selling in a particular stock takes place at the specialists post. A computer monitor shows all bid and ask prices for a stock in addition to the number of shares they are willing to buy or sell at the given bid ask price. Basically, Specialists execute the trades of other brokers, but they can also buy or sell shares for their own portfolios. When no other broker can be found to take the other end of a trade, the specialist must take the end of the trade where no one else can be found to do so. This is done to create liquidity, and is one of the biggest benefits to this system. Also, t his type of trading creates an auction market, where buyers and sellers are together in one location, and the best buy or sell orders win trades. They also act as a dealer when they have to execute a trade when there isn't a buyer or seller available using their own inventory. Again, this is meant to facilitate liquidity. NYSE stocks, until recently, couldn't trade certain NYSE stocks outside of a formal stock exchange, however the NYSE has since abolished this rule. This has created a small trading volume of NYSE stocks over ECN's. The current system on NASDAQ and most other OTC's incorporates dealers, who offer bid and ask prices to brokers who execute trades based on a listing of the current quotes from dealers. Although this is a very liquid market, dealers typically take a spread from the bid/ask price in exchange for the risk that they incur for holding the security.

Northern Victory in the Civil War Essay

This essay will analyze the varied factor that led to Northern victory in the Civil War between 1861-1864. The central reasons for this Union success can be categorized in economic, political, and military factors; some of these elements would include the southern focus on cotton monoculture, the union naval blockade, the confederate doctrine of State’s Rights, and the strength of union generals and their military tactics, between others. Overall, the north achieved dominance due to a combination of these reasons. Economic factors led to Northern victory as although both sides had great military potential, neither side had few methods to actually realize that potential. According to the Millennial edition of The Historical Statistics of the united states, during the time of the civil war the Union owned 71% of all the rail roads of the USA while the CSA only had a 29%. Also the Union had 90% of the manufactured items and a 97% of the firearms produced, while the CSA only had a 70% of the exports. Regarding the rail roads, this were of main importance, as the Union transported weapons, soldiers, ammo, and raw materials through this, so the fact that the northern states owned 21. 788 miles of rail roads didn’t only mean that they could transport all the machinery across the country but also, that the south was terribly limited in their transport, therefore the CSA had the disadvantage that the Union controlled rail roads across the country meaning, that they weren’t able to use their full potential on industry (cotton etc. or militarily as most of railroads were used for the moving of troops, while the north kept their industry stable and was able to move troops across the territory. More over, coming back to the production, and exports facts, although the southern states had most of the exports before the war (selling enormous amounts of cotton), as soon the war started their relations with Britain (who bought cotton to the south) broke out, so they had no econom ic strength behind their forces, as all their economy was based on agriculture, and had no industries. On the other side the Union had a totally industrialized economy where they were able to auto-sustain their states, therefore their economy before and during the war never changed, meaning that they were in perfect conditions as firearm production was extremely overwhelming over the one of the CSA and, they had money enough to go over a war and support their army with food, clothes, and weapons. In this way the North was highly superior to the south as they were financial base strong, so they could borrow internationally and purchase weapons and supplies abroad. Finally the fact that the Union had a population of 22. 000. 000 and the CSA of 9. 000. 000, which 5. 500. 000 of them were slaves, was also important because the north had enough people, so that factories never stop working, and still they had lots of soldiers and a big army, on the other side the south with a little population did not had enough for both activities, therefore some people had to stop working for going to the war. Between the southern statistics, we can find that the economic ones, are ridiculously overwhelmed by the ones of the Union, and this was mainly because their focus on monoculture, therefore if the cotton declined, then the confederate economy would be devastated, as they had a closed market, were almost most of their work was dedicated to one product. Unfortunately for the confederate states cotton trade rapidly declined during the civil war as many southerner believed that without the south’s cotton exports, Britain’s textile industry would collapse, causing terrible problems for the British Empire, and as a result England would join the war to fight the Union, however it did not work, and Britain started to buy cotton to other nations. As a result, the confederacy suffered crucially from under–industrialization as its only manufacturing plant The Tredegar Ironworks at Richmond, while the North had innumerable factories of the kind. This meant that the Confederates States weren’t able to maintain their railways, armies, and troops in the frontier, therefore the north had and advantage as southerners soldiers were unprepared for fighting and there railroads where in terrible conditions, so their little possession of railroads became even smaller, while the northern states were perfect due to their economic stability. In a civil war control of the oceans and rivers is often a critical point. The union had grater naval end industrial facilities, and decided to blockade the south to strangle its trade and wealth. The idea came from a commanding general, called Winfield Scott who designed this plan to win the war with as little violence as possible. The plan consisted in closing the main confederate ports; so in May 1861 when the blockade started the south was cut from almost all international trade. Therefore, the CSA’s economy was even worse than it was before, southern economy was now basically based in one factory, which was not even near to the production needed by the southerners to fight a war, and as a result the confederacy’s wealth didn’t resisted much war, so lines wouldn’t hold for much longer, and finally the northern forces would overthrow them one way or another, as southerners’’ railroads where getting each time worst, they had almost no weapons or fighting equipment as there trade was cut off, and they only had one factory so provide with ammo, weapons, clothes for all of the south. Overall, we can see clearly that the war totally destroyed the Confederacy’s economy. Firstly, cotton production was dripping quickly as the south tried to force Britain to join the war, this was devastating to the south as they almost had no income, and they where in the middle of a war. As a result that cotton production was not needed any more, the slaves had now much less work to do, and this meant that there were also men who had to look after them, as they were â€Å"dangerous†, therefore, there where less soldiers to fight against the north. At the same time, the war had a direct effect on the plantations as â€Å"It did not seem to matter whether a Union or confederate army crossed a plantation, either way the result was devastation, crops were trampled down, stock was stolen [†¦]†[1], this clearly shows the state of desperation of the south army, and the situation they were in. also the fact that some planters escaped from war-zone with their slaves, brought disruption, as the bad news of defeat was spread by planters and slaves into new areas. Therefore, planters had to run away because their property was being destroyed, this provoked even more decay in their production, agricultural farms, that could be used for feeding soldiers, weren’t worked any more by their owners, therefore the south had no way of getting food, as they couldn’t buy to any other country due to the blockade, and the local productions was getting destroy rapidly by the war, giving in this way a great advantage to the north, as southerners soldiers conditions were in some cases deplorable. Concluding, the fact that the south bet to a future, which slavery was supposed to guarantee, after the breaking of relations with the exterior, slavery was a thing of the past after only a year of war. Therefore, the confederacy who had spent a lot of money in bringing them from Africa and buying them, making slaves the column of their economy, was just a waste of time and money as they were useless, as they couldent fight, because if they were given a weapon the would use it to kill their owners and free themselves, and they were also a waste of soldiers as it required many whites to control them. Therefore, slaves who were the future of the CSA, ended up being a weight in the shoulders of southerners, as they created deficit, and this affected also, the confederacy’s economy. However, while economic reasons were clearly important in the northern victory, political factors, also played a mayor role. Jefferson Davis, President of the Confederate States of America, faced two challenges; one was to fight a war against the north and the second, to create a new nation. Therefore the south itself saw themselfeves in a bad position for fighting a war, because they had to care about to important things at the same time, and also they weren’t prepared to fight a war with another country like USA. Therefore, the lack of political organization, from the south, regarding to powers, was also an important issue, as the north was enormously superior, and had a better, and more organized political structure. As a result, the north fought a corporate war, while the south still had problems internally. Also confederate doctrine of state’s rights weakened the south as it created political disunity in the Confederacy. President Jefferson Davis, had to struggle with states governors, like Joe Brown, from Georgia or Zebulon Vance, from North Carolina, to get conscription approved, and even for basic military supplies. This disunity meant that the eastern and western fronts fought for resources, as most went to the east while the war was lost in the west. Firstly, this shows that states from the south did no believe they were going to win the war, as they started to withheld supplies to defend their own area, and this lead to Union victory, as they were separated, therefore, this didn’t just meant that they where more vulnerable as they were disunity, but also that they were weaker as states did not work together, each other to fight the north. Therefore the Union, saw the isolation of the southern states, and took advantage of it by attacking from different points, specially the west, and finally penetrating in this way through the North/south frontier, into the confederacy’s heart. Moreover, the role of foreign powers during the war was of main importance. Since the very beginning of the war, the Union made it clear that recognition of the Confederacy meant war to the Unites States. As a result, no nation appointed any diplomat officially to the confederacy; this meant that they received no diplomatic recognition. This was crucial, and one of the main aims of the North, because recognition to the south meant, a lot of income due to the cotton industry, and also weapons and machines to fight the war. Although the Union relied on its blockade to ensure victory, if the confederacy achieved recognition from Britain and France, this would have been much more difficult. Therefore, the fact that the CSA was not a recognized country before war, made things much more easier to the Union, as this meat no international support, and they were now isolated, clearly showing that they had no chances of wining the war without external help. Therefore this created conditions for the Union to win the war, as the fact that cotton trade was going down, and the only had one factory in the whole confederacy, made it clear that, they weren’t able to make it on their own, so the north clearly overwhelmed the south, as they had many factories to produce weapons, clothes etc. and also the support of European forces who sell weapons and machines to them; that’s why, it is so important that the CSA did not had a government, and a reason, of why they were so hurried up to become a nation. From the start of the war that Lincoln had a problem, which was how to unite the North sufficiently to make them want to fight and keep fighting. He needed an initiative, something that would give the northerners a reason to fight for. One way of doing this was through attacking slavery , and if we go back, some years before the war we could see that these really moved people (Uncle’s Tom Cabin), and although the civil war began over the secession of the South, and not over slavery, it was a fact which grew tensions between the Union and CSA before the war. Lincoln had to wait until Northern opinion was ready for the announcement of emancipation, where slaves would be set free. In 1862 the Atlantic slave trade was banned by the congress, but still people wanted more progress towards slavery destruction. Lincoln’s main reasons for this where: slavery had been already an important spark in the causes for the civil war, so to make sure war did not happen again. Free black were trying to enlist the Union’s army, and internationally the North would gain much support from the rest of the world, especially Europe, if the promised to crush slavery, and finally, in the same way the Declaration of Independence said, he thought that â€Å"all men are equal†. However, Lincoln suffered a resistance from his own cabinet, as they said that were private property, and under the constitution, it was not correct to do that. However, in July 1862, finally Lincoln’s cabinet agreed, and after the win of Antietam, the 17th of September, Lincoln decide that it was the right moment, son the 22nd of September of 1862 the preliminary proclamation was announced. It said that all slave owner who refused to make peace, all slaves in that territory would be freed on 1st of January 1863. Then, in January 1863 Lincoln put forward plans for gradual, compensated emancipation. After these, celebrations started all over the north. Rapidly runaway slaves joined the Union armies fighting the south, carrying wood, making roads and bridges between other things. On the other hand the confederacy tried to suppress all knowledge of the proclamation, but word spread around the south. Therefore, the proclamation strengthened the north as, people were encourage to fight, and were more enthusiastic, taking more participation and a major role in the war. Also, the fact that the Union was against slavery made international relations much easier to them, as other countries started to sympathize with the northerner’s actions, giving as a result a positive effect on the Unions economy. Also, the fact that slaves joined the army (178. 975, actually the 12. 5% of the whole army) was also of major help to the Northerners as they also started working at factories or scouting and searching for confederates or spying in the south. Therefore this led to Northern victory, as a huge amount of soldiers joined the army, internationals relations grew up, meaning more weapons and machines to fight the war, and finally, soldiers and people from the north had found the motivation to keep fighting. On the other hand, the proclamation weakened the Confederacy, slaves stop working at their plantations, or farms, therefore the had no workers, and that place was to be replace by the white, meaning in this way less men to fight the war. Slaves started rescuing Union soldier in the south, so they even started working against the confederacy, and as a result weakening their forces. Also, south’s international picture was terribly affected, as although eople already new the Southern states of the USA, worked a lot with slaves, with the proclamations, the Union was rapidly portrayed as heroes while the south became the villains of the story, and in this affected directly to the south’s relations with exterior, especially Europe. Therefore we can say that the effects of this proclamation led to northern victory, as 178. 975 new soldiers entered to the United States army to fight against the Confederacy. After proclamation, the North’s international view grew up in a positive way, while the southern one didn’t. This meant more exports and imports to the Union, which as a direct result made a huge significance in their trade and economy, and on the other side the Confederacy was left more isolated than it was before, meaning no weapons at all, and almost no income. The north had had found, an incentive to fight the war and give a quick finish to it, and the proclamation was the right push. Furthermore, workers were needed in the south to replace the place of the slaves, this meant less soldiers and less production for the confederacy.

High Failure Rates On Entrance Exams - 2845 Words

Issues related to the early discrepancy in student preparation came from a lack of codified secondary education in the nineteenth century when students were taught at home or by tutors and the fact that universities had vastly different opinions on what would be considered college ready. High failure rates on entrance exams could have been an artifact of the test design or for a way of the faculty to try and keep students out of the university. There was little consensus on what the students should know and what the students should have read and be versed in (Brubacher and Rudy 1976). Also, for all the failed students, the universities rarely enforced their entrance requirements and were generally lax in their application. There were†¦show more content†¦Even through the early 20th century, the admissions at prestigious universities like Harvard, Yale, and Princeton had nearly half of the students failing their college entrance exam (Brubacher Rudy, 1997). To this day, over 80% of universities offer developmental course in some form even though they have high enough entrance requirements where they should not be necessary. Terminology – A Horse of a Different Color The terms used to describe underprepared students has changed over the years, but still are used interchangeably. Remedial is the older term that generally refers to a program of study that is designed to correct a specific deficiency in a student’s academic profile. In the 1970’s, the term â€Å"developmental† began to be used by practitioners because it encompassed a more positive view of the total development of the student (Arendale 2005 p.72). Today most practitioners prefer the term developmental because it more accurately projects what the goals are for the students and does not have the same negative connotations of the students being deficient. Interestingly, the term remedial has long carried a negative connotation. Wyatt (1992) recounts the fact that in 1938 Harvard changed the name of its â€Å"Remedial Reading† course to â€Å"The Reading Class† and the enrollment went from 30 to 400 annually. The terms used to describe things do ma tter in the perceptions of those who are taking them and those who are paying for them. Remediation is still used by