Digital Subscriber Line

C H A P T E R Chapter Goals †¢ †¢ †¢ †¢ †¢ Identify and discuss different types of digital subscriber line (DSL) technologies. Discuss the benefits of using xDSL technologies. Explain how ASDL works. Explain the basic concepts of signaling and modulation. Discuss additional DSL technologies (SDSL, HDSL, HDSL-2, G. SHDSL, IDSL, and VDSL). Digital Subscriber Line Introduction Digital Subscriber Line (DSL) technology is a modem technology that uses existing twisted-pair telephone lines to transport high-bandwidth data, such as multimedia and video, to service subscribers. The term xDSL covers a number of similar yet competing forms of DSL technologies, including ADSL, SDSL, HDSL, HDSL-2, G. SHDL, IDSL, and VDSL. xDSL is drawing significant attention from implementers and service providers because it promises to deliver high-bandwidth data rates to dispersed locations with relatively small changes to the existing telco infrastructure. xDSL services are dedicated, point-to-point, public network access over twisted-pair copper wire on the local loop (last mile) between a network service provider’s (NSP) central office and the customer site, or on local loops created either intrabuilding or intracampus. Currently, most DSL deployments are ADSL, mainly delivered to residential customers. This chapter focus mainly on defining ADSL. Asymmetric Digital Subscriber Line Asymmetric Digital Subscriber Line (ADSL) technology is asymmetric. It allows more bandwidth downstream—from an NSP’s central office to the customer site—than upstream from the subscriber to the central office. This asymmetry, combined with always-on access (which eliminates call setup), makes ADSL ideal for Internet/intranet surfing, video-on-demand, and remote LAN access. Users of these applications typically download much more information than they send. Internetworking Technologies Handbook 1-58705-001-3 21-1 Chapter 21 Asymmetric Digital Subscriber Line Digital Subscriber Line ADSL transmits more than 6 Mbps to a subscriber and as much as 640 kbps more in both directions (shown in Figure 21-1). Such rates expand existing access capacity by a factor of 50 or more without new cabling. ADSL can literally transform the existing public information network from one limited to voice, text, and low-resolution graphics to a powerful, ubiquitous system capable of bringing multimedia, including full-motion video, to every home this century. Figure 21-1 The Components of an ADSL Network Include a Telco and a CPE Core network Existing copper Server ADSL ADSL 1. 5 to 9 Mbps 16 to 640 kbps Internet ADSL connection ADSL will play a crucial role over the next decade or more as telephone companies enter new markets for delivering information in video and multimedia formats. New broadband cabling will take decades to reach all prospective subscribers. Success of these new services depends on reaching as many subscribers as possible during the first few years. By bringing movies, television, video catalogs, remote CD-ROMs, corporate LANs, and the Internet into homes and small businesses, ADSL will make these markets viable and profitable for telephone companies and application suppliers alike. ADSL Capabilities An ADSL circuit connects an ADSL modem on each end of a twisted-pair telephone line, creating three information channels: a high-speed downstream channel, a medium-speed duplex channel, and a basic telephone service channel. The basic telephone service channel is split off from the digital modem by filters, thus guaranteeing uninterrupted basic telephone service, even if ADSL fails. The high-speed channel ranges from 1. 5 to 9 Mbps, and duplex rates range from 16 to 640 kbps. Each channel can be submultiplexed to form multiple lower-rate channels. ADSL modems provide data rates consistent with North American T1 1. 544 Mbps and European E1 2. 048 Mbps digital hierarchies (see Figure 21-2), and can be purchased with various speed ranges and capabilities. The minimum configuration provides 1. 5 or 2. 0 Mbps downstream and a 16-kbps duplex channel; others provide rates of 6. 1 Mbps and 64 kbps for duplex. Products with downstream rates up to 8 Mbps and duplex rates up to 640 kbps are available today. ADSL modems accommodate Asynchronous Transfer Mode (ATM) transport with variable rates and compensation for ATM overhead, as well as IP protocols. Internetworking Technologies Handbook 21-2 1-58705-001-3 Chapter 21 Digital Subscriber Line Asymmetric Digital Subscriber Line Figure 21-2 This Chart Shows the Speeds for Downstream Bearer and Duplex Bearer Channels Downstream bearer channels n x 1. 536 Mbps 1. 536 Mbps 3. 072 Mbps 4. 608 Mbps 6. 144 Mbps 2. 048 Mbps 4. 096 Mbps x 2. 048 Mbps Duplex bearer channels C channel Optional channels 16 Kbps 64 Kbps 160 Kbps 384 Kbps 544 Kbps 576 Kbps Downstream data rates depend on a number of factors, including the length of the copper line, its wire gauge, the presence of bridged taps, and cross-coupled interference. Line attenuation increases with line length and frequency, and decreases as wire diameter increases. Ignoring bridged taps, ADSL perfo rms as shown in Table 21-1. Table 21-1 Claimed ADSL Physical-Media Performance Data Rate (Mbps) 1. 5 or 2 1. 5 or 2 6. 1 6. 1 Wire Gauge (AWG) 24 26 24 26 Distance (feet) 18,000 15,000 12,000 9,000 Wire Size (mm) 0. 5 0. 4 0. 5 0. 4 Distance (km) 5. 5 4. 6 3. 7 2. 7 Although the measure varies from telco to telco, these capabilities can cover up to 95 percent of a loop plant, depending on the desired data rate. Customers beyond these distances can be reached with fiber-based digital loop carrier (DLC) systems. As these DLC systems become commercially available, telephone companies can offer virtually ubiquitous access in a relatively short time. Many applications envisioned for ADSL involve digital compressed video. As a real-time signal, digital video cannot use link- or network-level error control procedures commonly found in data communications systems. Therefore, ADSL modems incorporate forward error correction that dramatically reduces errors caused by impulse noise. Error correction on a symbol-by-symbol basis also reduces errors caused by continuous noise coupled into a line. ADSL Technology ADSL depends on advanced digital signal processing and creative algorithms to squeeze so much information through twisted-pair telephone lines. In addition, many advances have been required in transformers, analog filters, and analog/digital (A/D) converters. Long telephone lines may attenuate signals at 1 MHz (the outer edge of the band used by ADSL) by as much as 90 dB, forcing analog sections of ADSL modems to work very hard to realize large dynamic ranges, separate channels, and Internetworking Technologies Handbook 1-58705-001-3 21-3 Chapter 21 Asymmetric Digital Subscriber Line Digital Subscriber Line maintain low noise figures. On the outside, ADSL looks simple—transparent synchronous data pipes at various data rates over ordinary telephone lines. The inside, where all the transistors work, is a miracle of modern technology. Figure 21-3 displays the ADSL transceiver-network end. Figure 21-3 This Diagram Provides an Overview of the Devices That Make Up the ADSL Transceiver-Network End of the Topology Downstream channel(s) Duplex channel(s) Mux Error control XMTR D/A and A/D Line coupler Channel separation (FDM or ECH) Basic telephone service splitter Line Demux Duplex channel(s) Error control RCVR Basic telephone service ADSL transceiver–network end (Premises end is mirror image) To create multiple channels, ADSL modems divide the available bandwidth of a telephone line in one of two ways: frequency-division multiplexing (FDM) or echo cancellation, as shown in Figure 21-4. FDM assigns one band for upstream data and another band for downstream data. The downstream path is then divided by time-division multiplexing into one or more high-speed channels and one or more low-speed channels. The upstream path is also multiplexed into corresponding low-speed channels. Echo cancellation assigns the upstream band to overlap the downstream, and separates the two by means of local echo cancellation, a technique well known in V. 32 and V. 34 modems. With either technique, ADSL splits off a 4-kHz region for basic telephone service at the DC end of the band. Internetworking Technologies Handbook 21-4 1-58705-001-3 Chapter 21 Digital Subscriber Line Signaling and Modulation Figure 21-4 ADSL Uses FDM and Echo Cancellation to Divide the Available Bandwidth for Services FDM Upstream Basic telephone service Downstream Frequency Echo cancellation Upstream Basic telephone service Downstream 1 Mhz Frequency 1 Mhz An ADSL modem organizes the aggregate data stream created by multiplexing downstream channels, duplex channels, and maintenance channels together into blocks, and it attaches an error correction code to each block. The receiver then corrects errors that occur during transmission, up to the limits implied by the code and the block length. At the user’s option, the unit also can create superblocks by interleaving data within subblocks; this allows the receiver to correct any combination of errors within a specific span of bits. This, in turn, allows for effective transmission of both data and video signals. Signaling and Modulation This section includes the following: †¢ †¢ CAP and DMT Modulated ADSL ADSL Standards and Associations CAP and DMT Modulated ADSL DMT and CAP are line-coding methods for modulating the electrical signals sent over the copper wire in the local loop. Carrierless Amplitude and Phase (CAP) is a common line-coding method. CAP is a well-understood technology because of its similarity with QAM. Although CAP is well-understood and relatively inexpensive, some argue that it is difficult to scale because it is a single-carrier modulation technique and is susceptible to narrowband interference. DMT uses multiple carriers. At this point, DMT is capable of more speed than CAP. This is one reason that the ANSI committee T1E1. accorded it standards status in document T1. 413. This standard calls for 256 subbands of 4 KHz each, thereby occupying 1. 024 GHz. Each subband can be modulated with QAM 64 for clean subbands, down to QPSK. If each of the subbands can support QAM-64 modulation, then the forward channel supports 6. 1 Mbps. On the return path are 32 subbands, with a potential for 1. 5 Mbps. Internetworking Technologies H andbook 1-58705-001-3 21-5 Chapter 21 Signaling and Modulation Digital Subscriber Line CAP and DMT Compared CAP is a single-carrier technique that uses a wide passband. DMT is a multiple-carrier technique that uses many narrowband channels. The two have a number of engineering differences, even though, ultimately, they can offer similar service to the network layers discussed previously. Adaptive Equalization Adaptive equalizers are amplifiers that shape frequency response to compensate for attenuation and phase error. Adaptive equalization requires that the modems learn line characteristics and do so by sending probes and looking at the return signals. The equalizer then knows how it must amplify signals to get a nice, flat frequency response. The greater the dynamic range, the more complex the equalization. ADSL requires 50 dB of dynamic range, complicating adaptive equalization. Only with recent advances in digital signal processing (number crunching) has it become possible to have such equalization in relatively small packaging. Adaptive equalization is required for CAP because noise characteristics vary significantly across the frequency passband. Adaptive equalization is not needed for DMT because noise characteristics do not vary across any given 4-KHz subband. A major issue in comparing DMT with CAP is determining the point at which the complexity of adaptive equalization surpasses the complexity of DMT’s multiple Fourier transform calculations. This is determined by further implementation experience. Power Consumption Although DMT clearly scales and does not need adaptive equalization, other factors must be considered. First, with 256 channels, DMT has a disadvantage regarding power consumption (and, therefore, cost) when compared with CAP. DMT has a high peak-to-average power ratio because the multiple carriers can constructively interfere to yield a strong signal. DMT has higher computational requirements, resulting in more transistors than the transceiver chips. Numbers are mostly proprietary at this point, but it is estimated that a single transceiver will consume 5 W of power, even with further advances. Power consumption is important because hundreds or thousands (as carriers dearly hope) of transceivers might be at the central office, or CEV. This would require much more heat dissipation than CAP requires. Latency Another issue for DMT is that latencies are somewhat higher than with CAP (15). Because each subband uses only 4 KHz, no bit can travel faster than permitted by a QAM-64. The trade-off between throughput and latency is a historical one in data communications and has normally been settled in the marketplace. Speed DMT appears to have the speed advantage over CAP. Because narrow carriers have relatively few equalization problems, more aggressive modulation techniques can be used on each channel. For CAP to achieve comparable bit rates, it might be necessary to use more bandwidth, far beyond 1 MHz. This creates new problems associated with high frequencies on wires and would reduce CAP’s current advantage in power consumption. Internetworking Technologies Handbook 21-6 1-58705-001-3 Chapter 21 Digital Subscriber Line Additional DSL Technologies ADSL Standards and Associations The American National Standards Institute (ANSI) Working Group T1E1. 4 recently approved an ADSL standard at rates up to 6. 1 Mbps (DMT/ANSI Standard T1. 413). The European Technical Standards Institute (ETSI) contributed an annex to T1. 413 to reflect European requirements. T1. 413 currently embodies a single terminal interface at the premises end. Issue II expands the standard to include a multiplexed interface at the premises end, protocols for configuration and network management, and other improvements. The ATM Forum and the Digital Audio-Visual Council (DAVIC) have both recognized ADSL as a physical layer transmission protocol for UTP media. Additional DSL Technologies This section discusses the following DSL technologies: †¢ †¢ †¢ †¢ †¢ †¢ SDSL HDSL HDSL-2 G. SHDSL ISDN Digital Subscriber Line (DSL) VDSL SDSL Symmetric Digital Subscriber Line (SDSL) is a rate-adaptive version of HDSL and, like HDSL, is symmetric. It allows equal bandwidth downstream from an NSP’s central office to the customer site as upstream from the subscriber to the central office. SDSL supports data only on a single line and does not support analog calls. SDSL uses 2B1Q line coding and can transmit up to 1. 54 Mbps to and from a subscriber, or can be configured to offer a variable range of bandwidth up to 1. 45 Mbps. The symmetry that SDSL offers, combined with always-on access (which eliminates call setup), makes it a favorable WAN technology for small to medium businesses and branch offices, and can be an affordable alternative to dedicated leased lines and Frame Relay services. Because traffic is symmetrical, file transfer, web hosting, and distance-learning applications can effectively be implemented with SDSL. HDSL Originally developed by Bellcore, high bit-rate DSL (HDSL)/T1/E1 technologies have been standardized by ANSI in the United States and by ETSI in Europe. The ANSI standard covers two-pair T1 transmission, with a data rate of 784 kbps on each twisted pair. ETSI standards exist both for a two-pair E1 system, with each pair carrying 1168 kbps, and a three-pair E1 system, with 784 kbps on each twisted pair. HDSL became popular because it is a better way of provisioning T1 or E1 over twisted-pair copper lines than the long-used technique known as Alternative Mark Inversion (AMI). HDSL uses less bandwidth and requires no repeaters up to the CSA range. By using adaptive line equalization and 2B1Q modulation, HDSL transmits 1. 544 Mbps or 2. 048 Mbps in bandwidth ranging from 80ntrast to the 1. 5 MHz required by AMI. (AMI is still the encoding protocol used for the majority of T1. ) Internetworking Technologies Handbook 1-58705-001-3 21-7 Chapter 21 Additional DSL Technologies Digital Subscriber Line T1 service can be installed in a day for less than $1,000 by installing HDSL modems at each end of the line. Installation via AMI costs much more and takes more time because of the requirement to add repeaters between the subscriber and the CO. Depending on the length of the line, the cost to add repeaters for AMI could be up to $5,000 and could take more than a week. HDSL is heavily used in cellular telephone buildouts. Traffic from the base station is backhauled to the CO using HDSL in more than 50 percent of installations. Currently, the vast majority of new T1 lines are provisioned with HDSL. However, because of the embedded base of AMI, less than 30 percent of existing T1 lines are provisioned with HDSL. HDSL does have drawbacks. First, no provision exists for analog voice because it uses the voice band. Second, ADSL achieves better speeds than HDSL because ADSL’s asymmetry deliberately keeps the crosstalk at one end of the line. Symmetric systems such as HDSL have crosstalk at both ends. HDSL-2 HDSL-2 is an emerging standard and a promising alternative to HDSL. The intention is to offer a symmetric service at T1 speeds using a single-wire pair rather than two pairs. This will enable it to operate for a larger potential audience. It will require more aggressive modulation, shorter distances (about 10,000 feet), and better phone lines. Much of the SDSL equipment in the market today uses the 2B1Q line code developed for Integrated Services Digital Network. The Bell companies have insisted that using this SDSL at speeds higher than 768 kbps can cause interference with voice and other services that are offered on copper wire within the same wire bundle. The biggest advantage of HDSL-2, which was developed to serve as a standard by which different vendors’ equipment could interoperate, is that it is designed not to interfere with other services. However, HDSL-2 is full rate only, offering services only at 1. 5 Mbps. G. SHDSL G. SHDSL is a standards-based, multirate version of HDSL-2 and offers symmetrical service. The advantage of HDSL-2, which was developed to serve as a standard by which different vendors’ equipment could interoperate, is that it is designed not to interfere with other services. However, the HDSL-2 standard addresses only services at 1. 5 Mbps. Multirate HDSL-2 is part of Issue 2 of the standard known as G. SHDSL, and is ratified by the ITU. G. SHDSL builds upon the benefits of HDSL-2 by offering symmetrical rates of 2. 3 Mbps. ISDN Digital Subscriber Line ISDN digital subscriber line (IDSL) is a cross between ISDN and xDSL. It is like ISDN in that it uses a single-wire pair to transmit full-duplex data at 128 kbps and at distances of up to RRD range. Like ISDN, IDSL uses a 2B1Q line code to enable transparent operation through the ISDN â€Å"U† interface. Finally, the user continues to use existing CPE (ISDN BRI terminal adapters, bridges, and routers) to make the CO connections. The big difference is from the carrier’s point-of-view. Unlike ISDN, ISDL does not connect through the voice switch. A new piece of data communications equipment terminates the ISDL connection and shuts it off to a router or data switch. This is a key feature because the overloading of central office voice switches by data users is a growing problem for telcos. Internetworking Technologies Handbook 21-8 1-58705-001-3 Chapter 21 Digital Subscriber Line Summary The limitation of ISDL is that the customer no longer has access to ISDN signaling or voice services. But for Internet service providers, who do not provide a public voice service, ISDL is an interesting way of using POTS dial service to offer higher-speed Internet access, targeting the embedded base of more than five million ISDN users as an initial market. VDSL Very-High-Data-Rate Digital Subscriber Line (VDSL) transmits high-speed data over short reaches of twisted-pair copper telephone lines, with a range of speeds depending on actual line length. The maximum downstream rate under consideration is between 51 and 55 Mbps over lines up to 1000 feet (300 m) in length. Downstream speeds as low as 13 Mbps over lengths beyond 4000 feet (1500 m) are also common. Upstream rates in early models will be asymmetric, just like ADSL, at speeds from 1. 6 to 2. 3 Mbps. Both data channels will be separated in frequency from bands used for basic telephone service and Integrated Services Digital Network (ISDN), enabling service providers to overlay VDSL on existing services. Currently, the two high-speed channels are also separated in frequency. As needs arise for higher-speed upstream channels or symmetric rates, VDSL systems may need to use echo cancellation. Summary ASDL technology is asymmetric, allowing more bandwidth for downstream than upstream data flow. This asymmetric technology combined with always-on access makes ASDL ideal for users who typically download much more data than they send. An ASDL modem is connected to both ends of a twisted-pair telephone line to create three information channels: a high-speed downstream channel, a medium-speed duplex channel, and a basic telephone service channel. ADSL modems create multiple channels by dividing the available bandwidth of a telephone line using either frequency-division multiplexing (FDM) or echo cancellation. Both techniques split off a 4-kHz region for basic telephone service at the DC end of the band Synchronous Digital Subscriber Line (SDSL) provides variable, symmetric, high-speed data communication up to 1. 54 Mbps. But SDSL doesn’t allow analog on the same line, as ADSL does. SDSL uses 2B1Q line coding, a technology employed in ISDN and T1 services. SDSL is a viable business option because of its capability to transmit high-speed data over longer distances from the CO and because of its ease of deployment made possible by its spectral compatibility. High Bit-Rate DSL (HDSL) is a symmetric version of DSL that uses 2B1Q like SDSL, but over two-wire pairs. HDSL is targeted at business deployment because it offers full-rate symmetrical 1. 5 Mbps service. HDSL-2 is a standards-based version of HDSL offering symmetrical 1. 5 Mbps service like HDSL, but with a single twisted pair of wires. HDSL is full-rate and does not offer variable rates. G. SHDSL does offer multirate service with symmetrical speeds of up to 2. 3 Mbps. ISDN digital subscriber line (IDSL) is similar in many ways to ISDN. The primary difference is that IDSL is always on and can reach speeds up to 512 kbps with compression. IDSL uses 2B1Q line coding and does not support analog. On the other hand, IDSL does allow data communications over longer distances than other DSL options (up to 26,000 feet) and is considerably less expensive than ISDN service, in most cases. Because IDSL supports existing ISDN CPE, it makes it easy to convert from ISDN to IDSL. Internetworking Technologies Handbook 1-58705-001-3 21-9 Chapter 21 Review Questions Digital Subscriber Line Very-High-Data-Rate Digital Subscriber Line (VDSL) transmits high-speed data over short distances through twisted-pair copper telephone lines. VDSL technology is still in the definition stage, but additional research is required before it can be standardized. VSDL and ADSL are similar technologies. However, although VSDL transmits data at nearly 10 times the rate of ADSL, ADSL is the more complex transmission technology. Review Questions Q – Name the current versions of DSL technology. A – ADSL, SDSL, HDSL, HDSL-2, G. SHDL, IDSL, and VDSL. Q – What are the two-line coding methods used for ADSL? A – DMT and CAP. Q – Which versions of DSL offer symmetrical service? A – SDSL, HDSL, and HDSL-2. Q – What symmetrical version of DSL offers multirate service over a single pair of wire? A – G. SHDSL Q – How far of a reach can IDSL achieve from the CO? A – 26,000 feet. Q – What downstream and upstream rates are proposed for VDSL? A – The maximum downstream rate under consideration is between 51 and 55 Mbps over lines up to 1000 feet (300 m) in length. Downstream speeds as low as 13 Mbps over lengths beyond 4000 feet (1500 m) are also common. Upstream rates in early models will be asymmetric, just like ADSL, at speeds from 1. 6 to 2. 3 Mbps. For More Information ADSL Forum (http://www. adsl. com/) Cisco DSL Depot (http://www. isco. com/warp/public/779/servpro/promotions/dsldepot/) Glossary Terms †¢ G. SHDSL – Asymmetrical Digital Subscriber Line. The upstream data rate is different from the downstream (typically the downstream is greater than the upstream). It is applicable to many DSL technologies offered today; however, this term typically assumes DMT as defined in the ANSI T1. 413 specification. CPE – Customer premises equipment, including devices such as CSU/DSUs, modems, and ISDN terminal adapters, required to provide an electromagnetic termination for wide-area network circuits before connecting to the router or access server. This equipment was historically provided by the telephone company, but it is now typically provided by the customer in North American markets. †¢ Internetworking Technologies Handbook 21-10 1-58705-001-3 Chapter 21 Digital Subscriber Line Glossary Terms †¢ CSU/DSU – Channel service unit/data service unit. Provides electromagnetic termination of the digital (WAN) signal at the customer premises. Performs line conditioning and equalization functions, and responds to loopback commands sent from the central office. In North America, the customer supplies the device providing CSU/DSU functionality; outside North America, the telecommunications service provider usually provides this device. DMT – Discrete Multitone is the ANSI specified modulation technique for G. SHDSL (ANSI-T1. 413). DMT is theoretically capable of more speed than CAP. The key providers of DMT are Alcatel, Amati, Aware/ADI, and Orckit. Downstream – Refers to the transmission of data from the central office (CO or COE) to the customer premise equipment (CPE). HDSL – High-speed Digital Subscriber Line. This is a symmetrical modulation technique that uses two or three pairs of wires. HDSL2 – High-speed Digital Subscriber Line. This is a symmetrical modulation technique that can achieve speeds in the T1 (1. 5 Mbps) range using one copper pair. POTS – Plain old telephone service. QAM – Quadrature amplitude phase modulation. RG. SHDSL – Rate Adaptive Digital Subscriber Line. This refers to the CAP2 and QAM technologies that use variable data rates to maximize the utilization of various loop lengths. SDSL – Symmetric Digital Subscriber Line. This indicates a subscriber line service that utilizes the same data rate for upstream and downstream. This term is applicable to MDSL and HDSL technologies. Upstream – Refers to the transmission of data from the customer premises equipment (CPE) to the central office equipment (CO or COE). VDSL – Very-High-Data-Rate Digital Subscriber Line. This is a high-speed asymmetrical service in the 10 to 25 Mbps range, typically limited to less than 5,000 feet. The targeted application for this technology is a hybrid fiber copper system (fiber to the neighborhood). †¢ †¢ †¢ †¢ †¢ †¢ †¢ †¢ †¢ †¢ Internetworking Technologies Handbook 1-58705-001-3 21-11 Chapter 21 Glossary Terms Digital Subscriber Line Internetworking Technologies Handbook 21-12 1-58705-001-3

Navistar Company Essay

Executive Summary Trimco is a main supplier to Navistar. Navistar relies heavily on Trimco at their assembly plant. Navistar and Trimco must improve their quality management systems in order to have the right parts, in the right number shipped at the right time without any damages or defects. Navistar and Trimco must start imploring a more collaborative approach to their business process. Navistar needs to address their policy problems. Our last minute design changes seriously disrupt the supply process. The robbing of parts also creates a snowball effect of problems in other areas, or down the line. Trimco has several problems including high employee turnover, mixed technological capability with respect to manufacturing processes, and a lack of internal control. Areas of deficiencies must be jointly identified and solutions to these deficiencies must be collaboratively tackled. With these improvements, the cycle time from customer order to delivery should be reduced, which would allow a higher level of customer service at an overall lower cost. The delivery times for the custom-designed trucks should decrease with the recommended implementations. Navistar must identify the problem to Trimco. Trimco must be aware of these deficiencies and collaborate with Navistar to remedy these. Navistar must then look at the problem internally. Top management has given them support in this matter and they must be utilized. Input across different business functions must be taken. Working with other departments will help identify issues that were previously not seen. Incomplete parts can be monitored with a quality control system that compares parts ordered or required with actual parts sent. Last minute design changes must be stopped, as they are not sufficient to let Trimco manufacture the parts on time. Quality of the parts can be addressed by raising awareness of the issue, and by also ensuring packaging and handling of parts are done in meticulous order in order to reduce damages. The â€Å"robbed† parts must be stopped as it cr eates additional problems. It is a short-term fix that produces long-term negative effects. Issues Identification There are several issues for both Navistar and Trimco. I have asked shipping and receiving at both Navistar and Trimco to record the frequency of the trim problems as well as the root causes for each occurrence over a 6-month period. Firstly I will outline the problems here at Navistar. I find that we are storing/handling parts following improper receiving procedures, which include lost, misplaced, and damaged materials. Often parts contained within kits were damaged to the point where they could not be installed into truck interiors causing added costs for Trimco, and delay our assembly here at Navistar. We have also accepted parts that are defective. These parts sometimes went undetected until installation. These parts had to be either scrapped or returned to Trimco for replacement and credit. We must collaborate with Trimco in order to reduce their costs in this area. Communication between Trimco and Navistar will help reduction in total supply chain costs, which is a key measure in the strategic initiative that we are trying to plan in order to reduce these issues. Another issue is the robbing of parts for higher priority uses, which are caused due to supply failures. This of course translates to even more supply failures. This has caused continual shortages, lost stock, (which is the highest reason identified for trim part shortages) and excessive ordering. Another issue is last minute design changes. Navistar needs descriptions or specifications in describing the need in sufficient detail to ensure that the correct goods are ordered in the correct quality, at the correct time, at the correct place. It is considered one of the most important keys to successful strategic management. This is an issue for both Navistar and Trimco in that Navistar has to rework the parts, or order new parts to fill the demand. Specification outlining must be looked at in a strategic sense with Trimco and Navistar communicating different ideas in order to make these situations minimal. Another issue is the JIT suitability. Safety stock is still required which would beget calling it a just in time system. This must be addressed on both sides. Issues for Trimco include quality control problems. Shipping defective material, incorrect material, and even damaged parts, causes increased cost and decreased productivity for both Trimco and Navistar. Another issue for Trimco, which was also an issue for Navistar, was JIT suitability. It seems that at times Navistar expectation can be too high with the last minute specification changes,  which can lead to incorrectly punched parts, or incorrectly sent parts that has been an issue. Environmental and Root Cause Analysis The main cause of the issues for both Trimco and Navistar are quality issues. Both the supply plant and we the assembling plants are running into quality issues. Trimco Industries is a large supplier of automotive trim parts. It is also a very large Navistar supplier. Trimco faces several problems including mixed technological capability with respect to manufacturing processes; high employee turnover that affects employee training and awareness levels that impacts its ability to meet customer needs effectively. Shipping is an issue in that it lacks internal process. Correct parts aren’t always shipped, and the shipping of materials is not sufficient as damaged parts are ranked second as a reason for trim part shortages. Internally we have some issues as well. The last minute design change that we allow to occur, seriously disrupt the supply process. The stealing policy that allows workers to rob parts from one job for another only worsens existing problems. Inventory count, and easy identification of parts is negatively affected. This represents a short-term solution that equates to problems in the long run. The control over incoming parts seems to be an issue that needs to be addressed. Parts that are missing, damaged, defective or incorrectly sent, are being identified too late for Trimco to send appropriate replacement parts in time for assembly. Parts that are being stored at Navistar are being damaged between the time they are received from Trimco and the time they are required for production. This can equate to inefficient packaging, t even mishandling in our receiving area. This damage would indicate that inappropriate storage and handling procedures are being used at Navistar and Trimco. Navistar operates in a highly competitive industry. It has a long-standing history, and reputable background, but there is always pressure to reduce margins in any way possible in order to stay competitive in the industry. Navistar is in the cus tom truck business and currently has a 28.6% share in the North American market. At any given time 50-80% of our orders can be customized. Customers took time in designing their trucks to their specifications and expect timely delivery with impeccable quality. Missing and/or parts are directly impacting both the customer and bottom line costs. This represents 60% of trim part shortages. Trim shortages account for an estimated $200,000. This is a very generous estimation with the estimated cost potentially being far higher than this figure. The processes used both at Navistar and at Trimco are not sufficient to respond to last minute design changes, maintain a continuous supply of defect-free and correctly ordered parts, prevent internal stealing of parts and control the damage of parts during shipment. The quality management programs at both Navistar and Trimco need improvement to effectively change their current processes. All processes, both Navistar and Trimco’s must be in control, centered, and possess minimal variation. Strategically, if these problems were resolved, this would improve Navistar’s offering to our custom-designed truck customers. Trimco also has a high rate of attrition, which adds to the overall cost. This rate of turnover affects the training levels of employees and their ability to control processes, to respond to last minute design changes and to ensure the accuracy of trim part shipments. The cost of this employee attrition is high in many respects. Employees are paid $23 an hour in 1997. When these shortages occur there will be overtime needed which equates to $34.50 per hour. The constant turnover also has training costs, which can’t be measured in the employee’s hourly wage. The JIT system utilized is perhaps too stringent on time, especially with the issues at hand. A balance must be reached between a JIT system’s tightness and the ability of both the supplier and customer to work together to ensure a smooth and efficient supply chain system. There is not one root cause but rather two. The quality management programs at both Navistar and Trimco need improvement to effectively change their current processes. Strategically, if these problems were resolved, this would improve Navistar’s offering to the custom-designed truck customer. Navistar and Trimco’s JIT system must also be looked at. Alternatives and/or Options Again supplier relationships come to the forefront. Communication with Trimco is necessary in order to get a better understanding of Trimco’s problems, and where we think we can help. The JIT system utilized is   too stringent on time, especially with the issues at hand. A balance must be reached between a JIT system’s tightness and the ability of both the supplier and customer to work together to ensure a smooth and efficient supply chain system. Navistar employs a strategic centralized purchasing structure where all communication is done at Navistar headquarters. An alternative would be to have collaboration at both companies’ headquarters as to get a better line of communication. Another alternative would be for a better ERP system to be implemented. This would require additional costs, and would be a strategic move for the long run, but this could help with specification issues, as well as demand on both levels. Recommendations and Implementation The quality management programs at both Navistar and Trimco need improvement to effectively change their current processes. Strategically, if these problems were resolved, this would improve Navistar’s offering to the custom-designed truck customer. Some options that can help both Navistar and Trimco would be to delve deeper into their supplier relationship. Both parties can conduct a careful study of the processing line for both Navistar and Trimco in order to obtain a complete understanding of both companies manufacturing processes. The first step would be to notify Trimco of the supply problem. We understand the problem, and Trimco has had added costs, but we need to communicate with Trimco and have them understand how the supply problem effects Navistar’s bottom line, and ultimately how it affects our customers. This step should help open the lines of communication and help facilitate the beginning of the process. Next step would be to internally have top management involved. Top management already supports quality improvement efforts as it’s so important to Navistar’s bottom line. Let them know of the issues being faced. Support from management will help facilitate the necessary authority needed with Navistar to gain cooperation amongst the needed employees to help identify and resolve the supply problem. Upper management is primarily concerned with financial impact, but they must be aware of the impact of the problem both to the customer and those finances. The policy issues surrounding the problem with respect to last minute design changes and robbing and the deficiencies associated with Trimco must be communicated. Next would be to gain input from stakeholders. Input and feedback must be taken from other Navistar employees. Communication with Trimco is also vital in order to access additional data related to the problem as well as potential solutions to effectively resolve th e interior trim supply problem. Navistar can start by gaining input from the shipping manager, line manager, line employees, the chaser, quality managers, and design engineers. Trimco should also gain input from the shipping manager, shipping employees, and design engineers. This method will have multiple outcomes. It will start by identifying the problem to the company as a whole. The impact of the workers can be better communicated by identifying the issue. Feedback can be attained based on this as well. Line employees and shipping employees are first hand with respect to being effected by the problems, and they may voice their concerns. An added benefit of this will be that several implementation issues will be addressed before encountered. Communication and brainstorming will help identify the problems before implementation and this will be facilitated through a team approach. The design changes need to be stopped as it causing major delays and issues with Trimco. We must collaboratively agree to a set time frame that is feasible for both parties. Navistar can look at Trimco’s operation thoroughly—from design through manufacturing and delivery. Supplier relationship can take a bigger role, as Trimco is a major Navistar supplier. Communication is vital between Trimco and us. Some options and alternatives to other problems: To tackle incomplete shipments. A better EDI or implementing a joint ERP systems in which Trimco can improve control over parts being sent to Navistar with tracking being done in the ERP system. This will cost Trimco both financially and time wise, but will have a longer strategic impact in their business operations. An option to the parts quality problem would be to have Trimco have a better process when sending out parts to Navistar. Trimco needs to stop sending defective parts to Navistar, as Navistar has used these parts and ultimately had to scrap and replace them later on in their production. This is added cost and inefficiencies. Also damaged parts are second highest behind missing parts. Trimco will need to improve packaging and packing of shipping containers. On Navistar’s end, better storage of materials must be looked at in order to prevent the damage of parts while awaiting assembly. Parts can be stored in strategically   bins, or Navistar can look at other options such as storage towers. There would be added cost, but parts can be easily located, and can be much safer from damage. Monitor and Control Collaboration and communication between Trimco and Navistar is paramount in the monitoring and controlling of this outcome. Quality departments for both companies will be heavily involved in the monitoring of this implementation. Monitoring in the form of regular reports on defects, damages, and incorrect parts must be implemented in both companies. Reports to be conducted by shipping managers and line managers. There will be regular intervals where these figures will be displayed and addressed in a collaborative setting between the two companies. Integrating other business functions will be crucial as budgets can be looked at. Costs associated with these implementations should reflect a decrease in added costs and addressing expenses and looking at the budget can monitor this. The bulk of monitoring will go to the quality departments through internal reporting and tracking of damaged, defective, and incorrect parts.

Women's role in Hinduisim and Judaism Essay Example | Topics and Well Written Essays - 2000 words

Women's role in Hinduisim and Judaism - Essay Example This work intends to look into the role of women in Hinduism and Judaism. In order to understand what views the religions hold, the work primarily focuses on religious texts rather than contemporary social reality. This is so because what is practiced in the society is often slightly different from what is prescribed. Admittedly, Hinduism and Judaism are much older than many other religions. (Tuyizere 66). A look into the position of women in Hindu religion will provide the researcher with a number of contradicting views because while women enjoy equal status with men in some places, cultures, and texts, they seem to face many restrictions in some other cases. The reason may be that Hinduism is not a single religion, but is a union of various religions possessing considerably different views. Anyway, Vedas and Upanishads are considered as the basic tenets of Hinduism, and hence, the research on any subject in Hinduism should begin there. To begin with, a look into Vedas shows that a daughter is considered inferior to a son. To illustrate, Rig Veda presents the reader with a number of prayers for the birth of sons (Rig Veda I.91.20; III.1.23). These brave and religious sons are considered important because a son is necessary to perform religious rites to the ancestors. Thus, without a son, salvation of ancestors becomes a difficult task (Rig Veda V.85.25). As a result of this position, there is a degree of uneasiness associated with the birth of a girl child (Atharva Veda. VIII. 6. 25). Similarly, a look into Atharva Veda shows various charms and rituals in order to ensure the birth of a son (Atharva Veda VIII.6). Despite these differences, one can find references indicating equal position enjoyed by boys and girls in the Vedic society. For example, Atharva Veda (XI.5.18) shows that girls spent their early years in Brahmacharya ashram

Nelson Mandela Essay Example | Topics and Well Written Essays - 500 words - 3

Nelson Mandela - Essay Example On March 21, 1960, 69 unarmed citizens were murdered by the police as they were peacefully protesting against the pass laws in Sharpeville. This changed the political climate in the country. It resulted in the country’s first state of emergency. The Pan African Congress and the ANC were halted. Thousands of South Africans including Mandela and his friends were detained during the declared state of emergency. Mandela was sentenced to life imprisonment for fighting the apartheid. During his trial, he divorced his wife and got married to a Winnie Madikizela. They were blessed with two girls. They later on divorced in 1996. He spent 27 years of his lifetime in jail. He was freed in 1990. Upon his freedom from jail, he continued his fight against racial segregation and inequality. He also fought against the violence that was growing in South Africa. Mandela was honored with the Nobel Prize in 1993. In 1994, South Africa had its first ever democratic and fair election in which every one was given the opportunity to vote. He came out the victor and was the President. In his time as the President, he advocated for reconciliation, peaceful resolution of grievances by the citizens after years of autocratic laws against South Africans. Most people believe that without Mandela’s leadership, South Africa would probably have slipped into a bloody social war. He served until 1999 but refused to go for a second term. On April 27th, South Africa celebrates Freedom Day to signify their first ever democratic election.

Molecular Medicine Master Personal Statement Example | Topics and Well Written Essays - 250 words

Molecular Medicine Master - Personal Statement Example Based on the research and final project I am working on identifying a gene related to cholesterol disorder. I have studied biomedical studies and its incorporation into molecular medicine will enable me to clearly and concisely do my research in the stated field. Based on the level of education offered at your university, I wish to pursue masters in the field of molecular medicine as you produce only the best in the country. Based on my research methods and passion to identify and cure various diseases, I find myself suitable to learn and gain the necessary knowledge regarding molecular medicine. The developments faced in technology and the human genome projects have led to new ways of understanding and treating human diseases. The defects associated with single genes discoveries are very trivial and can be stopped and cured with man-month of efforts. My desire to understand various diseases like heart disease, cancer, and neurodegenerative disorders and estimation of their threat to people, based on each individual’s genotype has made me want to study molecular medicine. In conclusion, my passion to understand various diseases and how to cure them has been my driving force to study molecular medicine. Making an impact in this field will be an advantage to me as I would like to discover medicines to cure various harmful diseases and hope you will find me liable and capable to undertake the molecular medicine masters in your university.

Business Ethics & Corporate Social Responsibility Case Study

Business Ethics & Corporate Social Responsibility - Case Study Example One moral standard is core ethical values. The first component of core ethical values is trustworthiness. The recall and transparency in dealing with the crisis was effective in restoring the trust and confidence of consumers. The second component of core ethical values is responsibility. McCain took an important step in affirming that Maple Leaf was assuming full responsibility for the Listeria situation. The third component of core ethical values is caring. After realizing that Listeria had caused 21 deaths, Maple Leaf recalled its products. This is because the company did not want to be the cause of any more deaths in Canada. McCain said that if he had known in advance that Listeria in the meat products would cause 22 deaths, he would have taken all measures to save those lives. The fourth component of core ethical values is citizenship. As of 2009, Maple Leaf was following the new Listeria policy that was set up by the federal government. Because Listeria is ubiquitous in the env ironment, Maple Leaf has also taken measures to educate people about the fact that Listeria is resident in most processed foods, and as such it is important to boost one’s immune system as this is the basic way to fight the routine exposure to Listeria. The second moral standard is relativism. Maple Leaf failed to report that Listeria had been detected in their products as early as March 2007. This is because, unlike other meat processing plants, Maple Leaf felt confident because the USDA (United States Department of Agriculture) kept approving their products. The spokeswoman for Maple Leaf, Linda Smith, felt confident that if the USDA did not sanction the company, then any Listeria that had been detected was manageable and there was no need to cause mass panic. The third moral standard is egoism. Instead of focusing on the 22 people who had died from Listeria and the numerous sick people who consumed Listeria-infected products, Maple Leaf was more

Fair and Equitable Treatment on Foreign Investment and its Effects Essay - 1

Fair and Equitable Treatment on Foreign Investment and its Effects - Essay Example xposes the claimant to sectional or racial prejudice, or involves a leak of due process†.7 However, the jurisprudential doctrine of understanding the international law minimum standard has also been developed under international investment agreements.8 Essentially, there have been two views surrounding the understanding of the minimum standard of treatment, wherein breaches lead to violations of the FET standard. Firstly, the traditional view, understands the customary international law minimum standard as was reflected in the Neer case in the 1920s.9 For instance, in Alex Genin v Estonia,10 where the respond authorities revoked the claimant’s bank licence, the tribunal illustrated the conducts that would violate the minimum standard; they concluded that they â€Å"would include acts showing a wilful neglect of duty, an insufficiency of action falling far below international standards, or even subjective bad faith†.11 Thus, it appears clear that the tribunal deals with the traditional view because it believes that the FET standard would be breached in case State acts in bad faith. Secondly, the evolutionary view, considers that the customary international law minimum standard has been evolved since the Neer case. For example, in Azurix case,12 after analysing some awards inside and outside NAFTA the tribunal believed that the minimum requirement to satisfy the FET standard has evolved, and held that â€Å"such intention and bad faith can aggravate the situation but are not an essential element of the standard. It is also understood that the conduct of the State has to be below international standards but those are not at the level of 1927s†.13 Furthermore, in the Railroad case,14 the tribunal also discussed the evolution of the minimum standard and adopted the conclusion that â€Å"the minimum standard of treatment is constantly in a process of development including since Neer’s formulation†.15 Therefore, after examining the ways of interpreting the FET standard, it is logical to say that the controversy between the equating and plain meaning approaches is constantly reviewed in most cases. This, without a doubt, appears in many arbitral awards both within and outside NAFTA, because tribunals are quite reluctant to resolve this controversy.16 In addition, investors almost adopt an expensive view, as in the case of the Pope & Talbot case, while host States seek to support the NAFTA FTC approach of interpreting FET. However, it seems that none of the advanced approaches are able to provide persuasive reasons for their construction of FET, due to the fact that â€Å"this controversy is misguided, and the dichotomy presented by

Evaluation Review Paper Essay Example | Topics and Well Written Essays - 750 words

Evaluation Review Paper - Essay Example My personality has also changed as I was much introvert and isolated, but when I was required to deal with many people on daily basis, I attained confidence and way of interacting successfully with people. If I check the role of journaling in my progress professionally as well as personally, I consider it quite beneficial. I was to input my experiences and my feelings regarding my work and these narratives helped me to analyze my performance at work and to bring in improvements. Sometimes, I felt weird while dealing with my clients because I was not able to meet their demands, but later on, I learned to control my behavior and temper in order to facilitate them with what they wanted. When I started working in WHW, I had a different personality. As I have mentioned earlier on, I was very shy, introvert and confused, but after learning to work in an organizational setting, I saw improvement in my professional as well as personal personality. I am quite different from what I was before. When I used to see clothes and show the clients, what they needed as a personal shopper, I felt quite weird and confused and I easily lost my temper. However, with the passage of time and learning, I was much better in dealing with the clients without losing my temper. I spent hours and hours with them to show them what they needed. I learned a lot to work as a personal shopper. I marveled in my work to assist people who were in need of help. However, sometimes, I was also worried and disturbed when I was overloaded with additional work. The process of field seminar was beneficial. Initially, I was afraid of having a collaborative experience and in corresponding and interacting with different people, but when I started the process of corresponding with other people, it appeared quite interesting. I used to help my companion interns and we helped each other in our

Community vs. Cheers Essay Example | Topics and Well Written Essays - 750 words

Community vs. Cheers - Essay Example It featured a cast of mostly blue-collar characters who spent all their time hanging out together in a bar called Cheers. A more recent addition to the Thursday lineup is Community. It also features an ensemble cast of friends: A group of students at Greendale Community College. On the surface, these shows seem very similar. However, the styles of the two shows are actually quite different. Cheers was a traditional sitcom that followed the old rules for TV comedies, while Community is perhaps one of the most ground-breaking shows ever to air. The two shows do have some striking similarities. The apparent lead characters seem very similar at first glance. Cheers has Sam Malone, the former baseball player who owns Cheers. Sam is a little sleazy and an unrepentant womanizer, but he is a good man at heart. Community has Jeff Winger, the even sleazier former lawyer who has to attend a community college after he is exposed as having a fake degree. Like Sam, Jeff becomes the leader everyone depends on. Cheers has Diane Chambers, the prissy, self-righteous blonde whom Sam hires on the first episode as a waitress because he wants to sleep with her. Community has Britta, another self-righteous blonde who is nearly as prissy as Diane. Like Cheers, Community begins with the â€Å"alpha male† character trying to sleep with the blonde. Each of the two shows has a naà ¯ve, â€Å"dumb† character: Community’s Troy corresponds to Cheers’s Coach and his replacement, Woody.... Both use a mixture of long-running plotlines and episodic plots. Yet these shows have more differences than similarities. Cheers is filmed like a play in front of an audience with the three-camera format that has long been standard for sitcoms. Community is filmed in the modern style like a movie, in a single-camera format without an audience or laugh track. Filming style is not what makes the shows so different from one another, however. Community is best known for the clever way it â€Å"breaks the fourth wall,† the invisible wall through which the audience views the characters as their stories unfold. Traditionally, sitcom characters are supposed to go about their lives as if they are real people, unaware that they are fictional and being watched by the audience. This is the way that Cheers works, and this is the way things have always been done on television up until recent years. On Community, the characters verge on being self-aware, communicating to the audience with a wink and a nod that they know it’s not real, yet they still come across as loveable and believable characters. Despite the apparent standard â€Å"handsome white man as leader† and â€Å"beautiful blonde as love interest† cliche, over time the viewer begins to see that the key characters on Community are not Jeff and Britta. The most important character is Abed Nadir, a young Arab-American with Asperger’s syndrome, a type of autism. Abed is fixated on movies and television, and he sees his life as fictional plot. Each episode parodies a particular movie or genre of movies, but in a much more clever and subtle way than other TV shows have done before. Abed interprets everything that happens around