Wireless videophones Essay Example for Free

Wireless videophones Essay Wireless videophones and high-speed Internet access are a reality with the worlds first Third Generation mobile serviced, which were launched on October 1st 2001 by NTT DoCoMo in Tokyo, Japan. These has symbolized that human had enter a new era in mobile network technology. Facing with the ever advancing technologies, mobile network had integrated deep into our daily life style, cater for the needs to interact between friends and business organizations in a more effective, efficient and convenient way. At this moment, as we are discussing, there is a lot of network companies busily preparing for 3G or the Third Generation in mobile telephone devices. The precursors to this technology had began and entered the markets in year 2001 and 3G itself is due to have proliferated in the earnest by 2005. Singapore Telco, Singtel had announced a trail on the 3G network within CBD area at the last quarter of 2003. If 3G delivers what the developers promise, by 2004 we can look at broadband speeds via our mobile phones, plus a variety of new generation mobile devices that combine PC, PDA, camera, you name it, functionality. With 3G, data speeds will reach upwards of 2 Megabits per second (Mbps), which will give us high speed Web access and superlative quality video access via our trusty mobile communication devices. 3G also promises roaming capability throughout Europe, Asia and North America. 3G devices will deliver all that GPRS (General Packet Radio Services) can do, except a whole lot faster. Just imagine, how about catching up with that important client who never has time for a face to face meeting when hes in a taxi on his way to an airport at the other side of the globe? Consider watching your favourite television programmes on the MRT on your way home from work. How about consider connecting to your network, downloading files, transferring data, zipping off an email? With transfer speeds of more than 2 Mbps, tasks like these can be completed within seconds. Nokias concept team, for example, are currently considering four different categories for their 3G terminals: Â  Communicators These would be business tools, allowing users to quickly and efficiently log onto their networks, transfer information, wrote emails and synchronise information with conventional PC devices. Media phones These would perhaps give access to Internet services and include Personal Information Management, audio and data functions. Â  Imaging phones Sending of photos and video clips to our friends on the other side of the world within seconds. Â  Entertainment phones How about playing a game with friend at the other side of the globe. Or sending your distributor teams a video clip of your new office? To introduce, switch or implement a new technology can never be an easy task. It involved a lot of technology know how, equipments and researches. The bottom line is, a huge sum of money will be required. Take for example, other than GPRS technology, some other technology will be required to kick off the 3G network system. One of them is WCDMA, or Wideband Code Division Multiple Access, a wideband radio technique providing high data rates, and EDGE, or Enhanced Data rates for Global Evolution, a high-speed modulation technique that triples the capacity of GPRS. The various networks have spent a lot of money on this technology and will spend even more before the services are launched. In UK mobile networks have paid (22 billion just to use the required radio spectrum. According to Gartnet Dataquests survey in May 2002, Singapore will spend an estimate of US$19. 9 million in 2003 and US$102. 9 million in 2004 on the WCDMA infrastructure alone. That is not all, according to reports from Europe and Japan, which had started the 3G networking, had been under a lot of criticize. Most of their problems were mainly from the handsets and the network integration. Those countries in the preparation for the 3G launch had been very cautious on the setup. Europe and Japan experience will serve as a guidance for their future operation. Introduction. 3G wireless networks are capable of transferring data at high speeds of up to 384Kbps. Average speeds for 3G network will range between 64Kbps and 384Kbps, quite a jump when compared to common wireless data speeds in the U. S that are often slower than a 14. 4Kb modem. 3G is considered high speed or broadband mobile Internet access, and as time to come, 3G networks are expected to reach speeds of more than 2Mbps. In order to know the evolution of 3G, it might be interesting to get an idea on the history on the revolution of mobile networking . History of Mobile Networking System First Generation (1G). The first generation of mobile cellular telecommunications system appeared in the 1980s. The first generation was not the beginning of mobile communication, as there were several mobile radio networks in existence before then, but they are not cellular systems. The capacity of those early networks was much lower than that of mobile networks. And the support for mobility was weak. In mobile cellular networks the coverage area is divided into small cells, and thus the same frequencies can be used several times in the network without disturbing interference. This increase the system capacity. The first generation used analog transmission techniques for traffic, which was almost entirely voice. There was no dominant standard but several competing ones. The most successful standards were Nordic(TACS), and Advanced Mobile Phone Service (AMPS). Note that although the world is now busy moving into 3G networks, these first-generation networks, and many existing networks are growing. First Generation networks ( Extract from Introduction To 3G Mobile Communication) System Countries TACS/ETACS Austria, Azerbaijan, Bahrain, China, Hong Kong, Ireland, Italy, Japan, Kuwait, Macao, Malaysia, Malta, Philippines. Singapore, Spain, Sri Lanka, UAE, UK AMPS Argentina, Australia, Bangladesh, Brazil, Brunei, Burma, Cambodia, Canada, China, Georgia, Guam, Hong Kong, Indonesia, Kazakhstan, Malaysia, Mexico, Mongolia, Nauru, New Zealand, Pakistan, Papua New Guinea, Philippines, Russia, Singapore, South Korea, Sri Lanka, Tajikistan, Taiwan, Thailand, Turkmenistan, USA, Vietnam, Western Samoa Second Generation (2G), 2G evolve in the year 1991, in Finland. Second generation mobile network system use digital radio transmission. Thus the boundary line between first and second generation systems is obvious: it is the analog/digital split. The second generation networks have much higher capacity than the first generation systems. One frequency channel is simultaneously divided among several users (either by code or time division). Hierarchical cell structures- in which the service area is covered by macro and picocells enhance the system capacity even further. There are four main standards for second-generation systems,: Global System for Mobile ( GSM ) communications and its derivatives, Digital AMPS (D-AMPS), Code Division Multiple Access (CDMA {IS-95}) and Personal Digital Cellular (PDC) GSM uses the 900-MHz band is by far the most successful and widely used 2G system. PDC was eventually adopted by Japan. Generation 2. 5 (2. 5G), 2. 5G is a designation that broadly includes all advanced upgrades for the second generation networks. These upgrades may in fact sometimes provide almost same capabilities as the planned 3G systems. The boundary line between 2G and 2. 5G is a hazy one. It is difficult to say when a 2G becomes a 2. 5G system in a technical sense. When the wireless industry realized that it was going to be costly and technologically challenging to upgrade to 3G networks, 2. 5G emerged as an interim stage. These networks transfer data at speeds of up to 114Kbps, which is faster than traditional digital (2G) network. They are always on. A phone with 2. 5G services can alternate between using nets, sending or receiving test messages, and making calls without losing its connection to the Internet and email. Analysis of 3G Technology In the old days, when all phones were fixed rather than mobile, making a call involved establishing a direct electrical connection between your handset and the one you were calling. The same happens with 2G and 2. 5G networks, but instead of setting up a dedicated circuit, a small portion of the airwaves are reserved for your call. This is a really bad way of dividing up the available airwaves because it means that the spaces and pauses in speech get the same priority as the words. 3G networks change all this. Instead of reserving airspace each conversation is chopped up into packets, each one of which is labelled with a code denoting which dialogue it is from. The wireless literate generation of today (aged 12 35) provides a snapshot of tomorrows society and its drivers. The new generation is creating new usage patterns in favour of messaging and visual content. For them, messaging e. g SMS text messaging is the most natural way of personal communication. Instant communication is about being able to create and consume content (greetings, notes, snapshots/ postcards, moving pictures, instant voicemail) on the fly, and about filling transit moments with meaningful experiences. The mobile phone has become a personal trusted device that is capable of life management and enrichment, thanks to higher data rates and evolutionary user interfaces that have increased the simplicity and usability of terminals. Traditionally the major service has been voice but there has been an evolutionary step in 3G from Short Messaging Service (SMS) to 3GPP defined Multimedia Messaging, incorporating digital images and video clips with text or voice annotations. Industry analysts estimate that vendors are currently allocating from $200 billion in research and development resources to specify, design and manufacture infrastructure for evolving 3G networks. Of the 3G licenses currently awarded, more than 90 percent of those operators have specified WCDMA as their core 3G technology. Observers point out that, given this expected dominance of WCDMA as the 3G standard, this technology will undoubtedly receive the majority of RD funding and will yield the earliest, most extensive and most reliable product availability. What is WCDMA? WCDMA Wideband Code Division Multiplex Access (WCDMA) is the radio frequency technology indicated for all UMTS (Universal Mobile Telecommunication Services) networks, and WCDMA is widely expected to be the dominant technology for 3G networks worldwide. WCDMA supports high capacity, multiple simultaneous services and bit-rate performance of up to 2Mbit/s. But as a wideband (5 MHz channels) technology, WCDMA presents deployment challenges when implemented on narrow frequency allocations. When evaluating WCDMA infrastructure, operators should consider system solutions that provide well-established Third Generation Partnership Project (3GPP)-compatibility and that the resource allocation capabilities follow UMTS traffic class guidelines and Quality of Service attributes, allowing operators to optimize service differentiation. Modular designs allow these solutions to scale quickly to meet escalating network traffic demands. These same design advantages will allow these WCDMA solutions to be adapted to meet the demand for location-based services, personalized messaging and packet data traffic volumes that will define the coming wireless IP networks. These advanced WCDMA systems will also support seamless integration with GSM networks. 3G Concepts And Technology for Business 3G will be primarily driven by services and applications, not technology, although technologies such as Java, WAP, Bluetooth, SynchML and IPv6 have enabled third party application developments to meet users end-to-end service needs and expectations. The Mobile Internet will bring an explosion in the number of new applications a 3G hypermarket of services creating new marketing and revenue channels. Few business leaders are likely to turn down an opportunity to get an extra 10% of productivity from their mobile workforces, especially if it only costs a fraction of the reward. Third-generation (3G) wireless networks could facilitate this kind of return on investment (ROI) by extending desktop business-application, database, and intranet access into the mobile environment. 3G is an improvement over current networks, which deliver data and voice at no more than double the speed of dialup modems. The 3G infrastructure will eventually be able to transmit text, voice, video, and multimedia to a mobile handset with an always-on connection that is five times faster than a dialup modem. Initially, data-transfer rates may only equal todays dialup modem speeds, but that is still fast enough to make wireless service attractive to businesses seeking efficiency gains. Japans NTT DoCoMo turned on the worlds first 3G network in October 2001. Other mobile operators are conducting 3G trials in the United States and Europe, with plans to go live this year. The challenges include the complexity and costs of upgrading carrier networks and telephone handsets to handle 3G multimedia transmissions. Companies that adopt 3G networking for their mobile workforces within the next two years should expect limited coverage areas and the typical problems associated with any emerging technology. IDC recommends that company executives seeking 3G wireless connectivity should decide exactly why they want the service and pinpoint the efficiency points they need in order to recoup their investment costs in less than two years. Early adopters should measure the specific benefits of connecting mobile employees-reduced paperwork, faster collection of customer data, higher accuracy-and know which group of mobile employees will get the service first and why. In Europe, if an operator does not move fast into wireless data (3G) then the market will start to move without it threatening disintermediation for the laggards. At such, licences of the wideband connection, which carry new content-rich data and video-streaming services, cost up to US$10 billion in Italy and $45 billion in Germany respectively. (Source : Global Telecoms Business magazine). In both Japan and Korea, there is also a significant raise in the subscription in 3G mobile usage, stimulating the economic movement in the countries. In what ways can 3G networks be applied ? Application and Advantages, Multimedia Messaging Multimedia Messaging Service, or MMS, is a messaging service for the mobile environment standardized by the WAP Forum and 3GPP. For consumers, MMS is very similar to Short Message Service (SMS): it provides automatic, immediate delivery of user-created content sent primarily from phone to phone. MMS also provides support for email addressing, so messages can be sent to email. In addition to text, an MMS message sent to or from the Nokia 6650 phone can contain still images, voice or audio clips, and video. An MMS message is a multimedia presentation in one entity; it is not a text file with attachments. MMS delivers a location independent, total communication experience and is a simple, logical extension of SMS, also providing a similarly solid and reliable platform on which the operator can build additional services and increase service differentiation. Rich Call Rich call is an audio conversation supported by concurrent access to an image or data and allows users to not only listen to what I say but also see what I mean. Multiple simultaneous media types such as messaging, voice and video games can be started and ended independently but without the need to obtain the information first and then call back. Mobile Internet Mobile Internet is not just todays internet accessed from a mobile device (although it will of course still be possible,) but instead applications will provide users with personalised, context dependent and interworking applications. The scope of these services will cover areas such as information, entertainment, travel and personal information management. Many will be wholly or partly sponsored by advertisers, be location aware and have mCommerce integration. Multimedia streaming and downloading In 3G, enhanced bandwidth capabilities and advanced terminals enable video and audio, either real time or near real time or download. Eg, two way video conferencing with audio, video streaming. Streaming Media Services Audio streaming (eg MP3) is seen as the first widespread mainstream service to generate revenue through increased data traffic, attracting well off, music consuming and impatient twenty to thirty something generation consumers to subscribe to higher Quality of Service access. Although these services are available, to some extent, through 2. 5G terminals and networks, the bandwidth vs capacity evolution suggests that the real enabler for mass market service is WCDMA radio access. Streaming alleviates the need for a large memory resource in the terminal since only a small sample of the video or music data resides there at any one time. Copyright is also less of an issue because at no time is the entire data stored in the device. Entertainment There are two types of entertainment passive and interactive (games and media ie TV. ) Users will be able to connect to online multi platform gaming experiences or download, try out and purchase games. Handsets will allow inter operability though WAP, GPRS, Java and Symbian OS, making play possible across handset manufacturers. 3G Problems and Disadvantages, As we have mentioned earlier on, 3G is not flawless. Japan NTT was hit with the lack of delicated applications written for broadband speeds of 384 Kbps and handsets were designed for voice-centric application. Many people had to carry 2 handsets to ensure national coverage. Handset Problems, all the extra tasks will put something of a burden on the handset. At the moment screens on phones are small, they are difficult to type or get data into and they typically only work with one mobile phone technology.

Essay on Colonialism: Comparisons Between Things Fall Apart and Histori

Nigerian Women and Colonialism: Comparisons Between Things Fall Apart and Historical Accounts. Chinua Achebe is arguably the best known African writer of the twentieth century. And more than any other writer, he has shaped the world's idea of what African literature is. As Rose Mezu states, "Things Fall Apart is significant because it began the vogue of African novels of cultural contact and conflict" (Mezu 1). This is a highly influential position for a single writer. So what was Achebe's purpose in writing his novels? What does he hope to accomplish? According to Cora Agatucci's summary of Achebe's essay, "The Novelist as Teacher," she writes, " Achebe describes a dual mission to educate both African and European readers, to reinstate a sense of pride in African cultures and 'to help my society regain belief in itself and put away the complexes of years of denigration and self-abasement'" (Agatucci). So Achebe's purpose for writing is to overcome the stereotypes of Western readers that Africans are primitive savages with no sense of culture or history, and to combat the internalization of these stereotypes by his fellow countrymen. So where does Achebe's purpose for writing his novels leave women and are the gender roles as described in Things Fall Apart culturally accurate? Before this question can be accurately be answered; gender roles both in history and in Achebe's novel must be addressed. Specifically, what roles did men and women play in society in all three stages of Nigeria's more recent history? In the last 200 years of Nigeria's history, there have been basically three distinct phases in government: pre-colonial rule overall by Muslims (there were some tribes unaffected by this rule), colonial r... ...~womanist/1995/mezu.html "Nigeria." Encarta Encyclopedia. 3 July 2001. http://encarta.msn.com/find/concise.asp? mod=1&ti=761557915&page=2 "Nigeria." U.S. Department of State, Human rights Reports for 1999. 30 June 2001. http://www.state.gov/www/global/human_rights/1999_hrp_report/nigeria.html Ogunsuyi, Austin. "Women in Africa." African Cultures Page. 30 June 2001. http://africancultures.about.com/culture/african cultures/library/weekly/ aa011401a.htm Rojas, Maria. "Women in Colonial Nigeria." African Postcolonial Literature in English in the Postcolonial Web Page. 30 June 2001. http://landow.stg.brown.edu/ post/nigeria/colonwom.html ----- "Women in Pre-Colonial Nigeria." African Postcolonial Literature in English in the Postcolonial Web Page. 30 June 2001. http://landow.stg.brown.edu/ post/nigeria/precolwon.html

Productivity Improvement Techniques

These twelve productivity improvement techniques are explained as follows:- 1. Value Engineering (VE) : Value Engineering (VE) is the process of improving the value of a product at every stage of the product life cycle. At the development stage, VE improves the value of a product by reducing the cost without reducing quality. At the maturity stage, VE reduces the cost by replacing the costly components (parts) by cheaper components. VE also tries to improve the value and quality of the product. Value is the satisfaction which the consumer gets by using the product.VE tries to give maximum value for a lowest price. 2. Quality Circles (QC) : The concept of Quality Circles (QC) was introduced in 1960 in Japan. QC is a small group of employees who meet regularly to identify, analyse, and solve problems in their department. The QC members advise the management to implement new methods to solve work-related problems. QC increases the productivity. 3. Financial and Non-Financial Incentives : The organisation must motivate the employees by providing financial and non-financial incentives.The financial incentives include better wages and salaries, bonus, etc. The non-financial incentives include better working conditions, welfare facilities, worker's participation in management, etc. 4. Operations Research (OR) : Operations Research (OR) uses mathematical and scientific methods to solve management problems, including problems of productivity. QR technique uses a scientific method to study the alternative courses of actions and to select the best alternative. OR uses techniques such as linear programming, game theory, etc. to make the right decision. Thus, QR helps to improve productivity. 5. Training : Training is a process of increasing the knowledge and skills of the employees. Training is a must, for new employees and experienced employees. Training increases the efficiency of the employee. Thus, training results in high productivity. 6. Job Enlargement : Job Enlarge ment is a horizontal expansion of a job. It is done to make jobs more interesting and satisfying. It involves increasing the variety of duties. For e. g. typist may be given the job of accounts writing in addition to the typing work. This technique is used for lower level jobs. 7. Job Enrichment : Job Enrichment is a vertical expansion of a job. It makes routine jobs more meaningful and satisfying. It involves providing more challenging tasks, and responsibilities. For e. g. a manager who prepares performance reports is asked to make plans for his department. Job Enrichment technique is used for higher-level jobs. 8. Inventory Control : There must be a proper level of inventory.Overstocking and under stocking of inventories must be avoided. Overstocking of inventories will result in blocking of funds and there are chances of spoilage or misuse of materials. Under stocking of inventories will result in shortages. This will block the smooth flow of production, and so the delivery sche dules will be affected. 9. Materials' management : Materials' management deals with optimum utilisation of materials in the manufacturing process. It involves scientific purchasing, systematic store keeping, proper inventory control, etc.The main objective of materials' management is to purchase the right quantity and quality materials, at the right prices, at the right time, to maintain favourable relations with suppliers, to reduce the cost of production, etc. 10. Quality Control : The main objective of quality control is to produce good quality goods at reasonable prices, to reduce wastages, to locate causes of quality deviation and to correct such deviations, to make the employees quality conscious, etc. 11. Job Evaluation : Job Evaluation is a process of fixing the value of each job in the organisation.It is done to fix the wage rate for each job. A proper job evaluation increases the moral of the employees. This increases the productivity. 12. Human factor engineering : Human factor engineering refers to the man-machine relationship. It is designed to match the technology to a human requirement. The term Ergonomics has originated from the Greek word ‘ergos' meaning ‘Work' and ‘nomikos' meaning ‘Law'. So, it means ‘Law of Work'. It tells us how to fit a job to a man's psychological and physiological characteristics to increase human efficiency and well-being.

Harappa Capital City of the Indus Civilization

Harappa is the name of the ruins of an immense capital city of the Indus Civilization, and one of the best-known sites in Pakistan, located on the bank of the Ravi River in central Punjab Province. At the height of the Indus civilization, between 2600–1900 BCE, Harappa was one of a handful of central places for thousands of cities and towns covering a million square kilometers (about 385,000 square miles) of territory in South Asia. Other central places include Mohenjo-daro, Rakhigarhi, and Dholavira, all with areas over 100 hectares (250 acres) in their heyday. Harappa was occupied between about 3800 and 1500 BCE: and, in fact, still is: the modern city of Harappa is built atop some of its ruins. At its height, it covered an area of at least 250 acres (100 hectares) and may have been about twice that, given that much of the site has been buried by the alluvial floods of the Ravi river. Intact structural remains include those of a citadel/fortress, a massive monumental building once called the granary, and at least three cemeteries. Many of the adobe bricks were robbed in antiquity from the significant architectural remains. Chronology Period 5: Late Harappa Phase, also known as the Localization phase or Late declining phase, 1900–1300 BCEPeriod 4: Transitional to Late Harappa, 1900-1800 BCPeriod 3: Harappa Phase (aka Mature Phase or Integration era, the major urban center of 150 ha and between 60,000–80,000 people), 2600–1900 BCEPeriod 3C: Harappa Phase C, 2200–1900 BCEPeriod 3B: Harappa Phase B, 2450–2200 BCEPeriod 3A: Harappa Phase A, 2600–2450 BCEPeriod 2: Kot Diji Phase (Early Harappan, incipient urbanization, ca 25 hectares), 2800–2600 BCEPeriod 1: pre-Harappan Ravi aspect of the Hakra phase, 3800–2800 BCE The earliest Indus phase occupation at Harappa is called the Ravi aspect, when people first lived at least as early as 3800 BCE. At its beginnings, Harappa was a small settlement with a collection of workshops, where craft specialists made agate beads. Some evidence suggests that people from older Ravi phase sites in the adjacent hills were the migrants who first settled Harappa. Kot Diji Phase During the Kot Diji phase (2800–2500 BC), the Harappans used standardized sun-baked adobe bricks to build city walls and domestic architecture. The settlement was laid out along gridded streets tracing the cardinal directions and wheeled carts pulled by bulls for transporting heavy commodities into Harappa. There are organized cemeteries and some of the burials are richer than others, indicating the first evidence for social, economic, and political ranking. Also during the Kot Diji phase is the first evidence for writing in the region, consisting of a piece of pottery with a possible early Indus script. Commerce is also in evidence: a cubical limestone weight that conforms to the later Harappan weight system. Square stamp seals were used to mark clay seals on bundles of goods. These technologies likely reflect some sort of trade interactions with Mesopotamia. Long carnelian beads found at the Mesopotamian capital city of Ur were made either by craftsmen in the Indus region or by others living in Mesopotamia using Indus raw materials and technology. Mature Harappan Phase During the Mature Harappan phase (also known as the Integration Era) [2600–1900 BCE], Harappa may have directly controlled the communities surrounding their city walls. Unlike in Mesopotamia, there is no evidence for hereditary monarchies; instead, the city was ruled by influential elites, who were likely merchants, landowners, and religious leaders. Four major mounds (AB, E, ET, and F) used during the Integration period represent combined sun-dried mudbrick and baked brick buildings. Baked brick is first used in quantity during this phase, especially in walls and floors exposed to water. Architecture from this period includes multiple walled sectors, gateways, drains, wells, and fired brick buildings. Also during the Harappa phase, a faience and steatite bead production workshop blossomed, identified by several layers of faience slag—leftover material from the production of the glassy ceramic known as faience—chert blades, lumps of sawn steatite, bone tools, terracotta cakes and large masses of vitrified faience slag. Also discovered in the workshop were an  abundant number of broken and complete tablets and beads, many with incised scripts. Late Harappan During the Localization period, all of the major cities including Harappa began to lose their power. This was likely a result of shifting river patterns that made the abandonment of many cities necessary. People migrated out of the cities on the river banks and up into smaller cities the higher reaches of the Indus, Gujarat and Ganga-Yamuna valleys. In addition to large-scale de-urbanization, the Late Harappan period was also characterized by a shift to drought-resistant small-grained millets and an increase in interpersonal violence. The reasons for these changes may be attributed to climate change: there was a decline in the predictability of the seasonal monsoon during this period. Earlier scholars have suggested catastrophic flood or disease, trade decline, and a now-discredited Aryan invasion. Society and Economy Harappan food economy was based on a combination of agriculture, pastoralism, and fishing and hunting. Harappans farmed domesticated  wheat  and  barley, pulses and  millets, sesame,  peas, chickpeas, and other vegetables. Animal husbandry included humped (Bos indicus) and non-humped (Bos bubalis) cattle and, to a lesser degree, sheep and goats. The people hunted elephant, rhinoceros, water buffalo, elk, deer, antelope and  wild ass. Trade for raw materials began as early as the Ravi phase, including marine resources, wood, stone, and metal from the coastal regions, as well as neighboring regions in Afghanistan, Baluchistan and the Himalayas.  Trade networks  and migration of people into and out of Harappa were established by then as well, but the city truly became cosmopolitan during the Integration era. Unlike  Mesopotamias royal burials  there are no huge monuments or obvious rulers in any of the burials, although there is some evidence for some differential elite access to luxury goods. Some of the skeletons also show injuries, suggesting that interpersonal violence was a fact of life for some of the citys residents, but not all. Part of the population had less access to elite goods and a higher risk of violence. Archaeology at Harappa Harappa was discovered in 1826 and first excavated in 1920 and 1921 by the Archaeological Survey of India, led by Rai Bahadur Daya Ram Sahni, as described later by M.S. Vats. Over 25 field seasons have occurred since the first excavations. Other archaeologists associated with Harappa include  Mortimer Wheeler, George Dales, Richard Meadow, and J. Mark Kenoyer. An excellent source for information about Harappa (with lots of photographs) comes from the highly recommended at Harappa.com. Selected Sources: Danino, Michael. Aryans and the Indus Civilization: Archaeological, Skeletal, and Molecular Evidence. A Companion to South Asia in the Past. Eds. Schug, Gwen Robbins ,  and Subhash R. Walimbe. Malden, Massachusetts: Wiley Blackwell, 2016. Print.Kenoyer, J. Mark, T. Douglas Price, and James H. Burton. A New Approach to Tracking Connections between the Indus Valley and Mesopotamia: Initial Results of Strontium Isotope Analyses from Harappa and Ur. Journal of Archaeological Science 40.5 (2013): 2286-97. Print.Khan, Aurangzeb, and Carsten Lemmen. Bricks and Urbanism in the Indus Valley Rise and Decline. History and Philosophy of Physics (physics.hist-ph) arXiv:1303.1426v1 (2013). Print.Lovell, Nancy C. Additional Data on Trauma at Harappa. International Journal of Paleopathology 6 (2014): 1-4. Print.Pokharia, Anil K., Jeewan Singh Kharakwal, and Alka Srivastava. Archaeobotanical Evidence of Millets in the Indian Subcontinent with Some Observations on Their Role in the Indus Civilizatio n. Journal of Archaeological Science 42 (2014): 442-55. Print.Robbins Schug, Gwen, et al. A Peaceful Realm? Trauma and Social Differentiation at Harappa. International Journal of Paleopathology 2.2–3 (2012): 136-47. Print.Sarkar, Anindya, et al. Oxygen Isotope in Archaeological Bioapatites from India: Implications to Climate Change and Decline of Bronze Age Harappan Civilization. Scientific Reports 6 (2016): 26555. Print.Valentine, Benjamin, et al. Evidence for Patterns of Selective Urban Migration in the Greater Indus Valley (2600-1900 BC): A Lead and Strontium Isotope Mortuary Analysis. PLoS ONE 10.4 (2015): e0123103. Print.