Standards for Technology in Automotive Retail

 
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13.3. DETAILED METHODS REVIEW

All access methods are grouped into two categories: wired and non-wired. Wired methods can be broken down further as dedicated line and non-dedicated line.

13.3.1. Wired Methods

Dedicated Line – Wired Method

A dedicated line is a telecommunications path between two points that is available 24 hours a day for use at those sites. It may be either a physical cable or a logically switched system. Therefore, the network speed is guaranteed and predictable. Unlike dial-up these lines are not shared. A dedicated line can be a physical path owned by the dealership or rented from a telephone company, in which case it is called a “leased line”. Examples of dedicated circuits include Digital Subscriber Line (DSL) and T-1 lines.

Non-Dedicated Line – Wired Method

A non-dedicated line is always shared among multiple sites. When referring to telephone circuits, it can be called a switched line. Sites share a fixed bandwidth while they are connected to the network. Consequently, the network speed is not guaranteed or predictable. Examples of non-dedicated circuits include dial-up lines and cable modems.

The nature of the line, dedicated or non-dedicated, only indicates if a fixed network bandwidth is reserved for the line. Either type of line still has the ability to access the Internet through public or private network infrastructures. Another way of looking at the differences in service would be to consider an example of electrical power delivery. If service is dedicated, it would provide a private power line running from the power plant directly to the dealership. All of the wattage that left the plant would arrive at the dealership. A non-dedicated service would have large wattage circuits starting at the plant and then divided throughout the city until they finally reached the dealership. Most of the time no difference between the services exist. However, when the dealership and neighboring businesses all put their air conditioners on high, power usage soars and the wattage available to each diminishes. In extreme cases, this can causes brownouts or even blackouts.

Dial Up – Wired Method

This is the most basic and widely available method to access to the Internet. Dial-up refers to a connection to a telephone system where the lines are shared. If the line is available, a connection is made and if not, a busy signal is received. A dial-up connection is established and maintained for limited time duration and the maximum connection speed is 56Kbps. Circuit and carrier limitations may prevent the modem from operating at full capacity. The equipment required to access the Internet via a dial-up line is a regular telephone line and a modem as well as an account from an Internet Service Provider (ISP). . The account should be a business-oriented account that will allow use with generic browser software. Services like AOL or EarthLink often require the use of special client software. Some providers require that access be made through their home page (portal). Both of these requirements can cause application performance and functionality problems.

To enhance the dial-up network throughput, the aggregated dial-up technology has been created. Sometimes referred to as line bonding, this “bandwidth-on-demand” technology combines two or more telephone lines into a single network connection. Manufacturers advertise that a maximum data rate of 230Kbps can be achieved. In areas where DSL is available, work is being done to bond multiple DSL circuits at even higher throughput. The major drawback is that some ISP‘s do not support this technology. If they do, the fee is usually higher as well. Newer products claim that the technology is not dependent upon the ISP and that, other than granting multiple accounts; the multiple connections are transparent to the ISP.

Table 13.1. Dial-up Internet Access

Key Factors of Dial-up   

Costs (Approx.)

Equipment/Install 56Kbps modems are under $100 and are often included with new PC’s.
Circuit Uses regular telephone line (at a cost of approx. $50/month). Multiple lines needed for larger dealers.
Usage Fees $15 –$50/month for unlimited access. Call to ISP may be a toll call in some areas.

Terms

Commitment RequiredUsually just one month.
Quality of Service Most often not guaranteed, but can be lower depending on time of day.

Bandwidth

Capacity Up to 56Kbps. Circuit and carrier limitations may prevent operating at the full capacity of the modem.
ConsistencyGood once established.
Latency (Delay) Initial time to connect can be lengthy or may require multiple attempts. ISP may drop the connection if the line is inactive for a period.
Availability  Generally good across Canada, Mexico, and U.S.

Installation

Complexity Dial-up is simple. Average users install it themselves. Aggregate dial-up is more complex and it may require professional installation.
Support for Business Use Support is built around standard installations on a single PC; support for business users is only as good as it is for any other user. Some ISPs may not support aggregate dial-up.
Life Span   Very good. Economics will keep alive.
Reuse Combination Possibilities Can be used for voice when not connected.

Integrated Services Digital Network (ISDN) – Wired Method

ISDN is a standard for digital transmission over ordinary telephone copper wire as well as over other media. ISDN is generally available from the telephone company in most urban areas in Canada and the United States as well as the major cities in Mexico. In concept, this is the integration of both analog or voice data together with digital data over the same network.

There are two levels of service: the Basic Rate Interface (BRI) intended for the home and the small enterprise, and the Primary Rate Interface (PRI), for larger businesses. Both rates include a number of B (bearer) channels and a D (delta) channel. The B channels carry data, voice, and other services. The D channel carries control and signaling information. The Basic Rate Interface consists of two 64Kbps B channels and one 16Kbps D channel. Thus, a Basic Rate user can have 64Kbps or 128Kbps service.

The Primary Rate consists of 23 B channels and one 64Kbps D channel. A portion of the B channels can be combined in any number to provide data capacity approaching 1.5Mbps. The remaining channels can be set aside for voice traffic. This arraignment can be a very attractive cost alternative to traditional voice service. In some cases, the money saved over traditional telephone costs will more than pay for the cost of the entire circuit.

The primary use for ISDN is for backup, rather than primary Internet connections. With the price of the dedicated T-1 circuits coming down and with some companies charging by the minute where ISDN is being used, T-1 technology is surpassing ISDN as the main Internet connection choice.

Table 13.2. ISDN Internet Access

Key Factors of ISDN   

Costs (Approx.)

Equipment/Install Equipment usually carrier provided. Install fees average $100.
Circuit BRI: $50 / month; PRI: $500 - $1,000 / month.
Usage Fees Unlimited hours. You may incur local and/or toll charges. Less expensive plans may be offered, with charges up to $4/hour after minimum hours. ISP fees for BRI service average an additional $50 – $100/ month. PRI service averages $100 - $1,000 /month.

Terms

Commitment Required Monthly. Price breaks for longer terms are available.
Quality of Service The carrier will guarantee service level.

Bandwidth

Capacity BRI service offers 64Kbps or 128Kbps with no expansion beyond that. PRI service can offer up to 1.5Mbps capacity.
ConsistencyVery good once established.
Latency (Delay) Initial time to connect can be lengthy or may require multiple attempts. ISP may drop the connection if the line is inactive for period.
Availability  Major markets in Canada, Mexico, and the U.S.

Installation

Complexity Professional installation required for both the circuit and the router.
Support for Business Use BRI is designed for use in small business. Demanding customers may find support insufficient.
Life Span   Uncertain. Many users are switching to xDSL where available.
Reuse Combination Possibilities In businesses with more than 15 telephone lines, combining voice and data on a PRI circuit can easily be cost justified.

Frame Relay –Wired Method

Frame relay service is designed for high-performance data transmission of traffic between local area networks (LANs) and between end points in a wide area network (WAN). Frame relay puts data in a variable-size unit called a frame and leaves any necessary error correction (retransmission of data) up to the end points, which speeds up overall data transmission. Since the incidence of error in digital networks is extraordinarily small, error correction is not a problem. For most services, the network provides a permanent virtual circuit (PVC), which means that the customer sees a continuous, dedicated connection without having to pay for a full-time leased line. The service provider determines the route each frame travels to its destination and can charge based on usage. An enterprise can select a level of service quality –prioritizing some frames and making others less important. Frame relay service is offered by all telephone carriers and is supported by the larger service providers. Fractional or full circuits provide service that can range in capacity from 64Kbps to 1.5Mbps.

Table 13.3. Frame Relay Inernet Access

Key Factors of Frame Relay   

Costs (Approx.)

Equipment/Install Average $1,000. Many carriers will waive install fees
Circuit $200 – $500/month based on capacity
Usage Fees ISP will charge $100 – $1,000/month based on capacity

Terms

Commitment RequiredUsually one-year minimum
Quality of Service Carrier engineers circuit to the installation. Level of service are guaranteed

Bandwidth

Capacity 64Kbps minimum with expansion up to 1.5Mbps
Consistency Circuit is shared, so results can vary slightly. Carrier will guarantee minimums and maximums
Latency (Delay) Circuit is shared so results will vary slightly. Carrier will guarantee maximum
Availability  Excellent in Canada, Mexico, and the U.S

Installation

Complexity Professional installation required for both the circuit and the router
Support for Business Use Because of the wide range of bandwidths, solutions for dealerships of any size can be found
Life Span   Many users are switching to xDSL where available, but carriers are committed to offerings. Prices are dropping to compete where xDSL is available
Reuse Combination Possibilities It is not ideally suited for voice or video transmission, each of which requires a steady flow of transmissions

T-1 - Wired Method

A T-1 line is a dedicated connection consisting of up to 24 channels - each having 64Kbps of capacity. A full T-1 uses all 24 channels to provide 1.5Mbps of capacity. A fractional T-1 uses any number of channels up to 24. One channel will provide 64Kbps of capacity. Two channels provide 128Kbps; and so on. T-1 and frame relay circuits are similar, however frame relay traffic is shared among multiple locations. Generally a T-1 line has better performance and is more reliable than a frame relay circuit. A T-1 line can also be set up to carry both voice and data, thereby reducing the number of voice lines in the dealership. This can help to justify the expense of a T-1.

Table 13.4. T-1 Internet Access

Key Factors of T-1   

Costs (Approx.)

Equipment/InstallAverage $1,000
Circuit From $300 - $500/month. Pricing may be distance related
Usage Fees ISP will charge $100 – $1,000/month based on capacity and distance

Terms

Commitment RequiredUsually one-year minimum
Quality of Service Level of service will be guaranteed

Bandwidth

Capacity128Kbps to 1.5Mbps
Consistency Excellent. Carrier will guarantee performance
Latency (Delay) Excellent. Carrier will guarantee performance
Availability  Excellent in Canada, Mexico, and the U.S

Installation

Complexity Professional installation required for both the circuit and the router
Support for Business Use Because of the wide range of bandwidths, solutions for dealerships of any size can be found
Life Span   Good. Only generic technology that offers this much bandwidth
Reuse Combination Possibilities In businesses with more than a dozen telephone lines, combining voice and data on a circuit may easily be cost justified

Cable Modem - Wired Method

Recently many cable companies have recognized the need for high-speed access to the Internet, and the distinct advantage they have in providing this service. Because cable companies already have a high-speed connection to many homes and businesses in the form of cable TV, they are able to rapidly deploy high-speed data communications by taking advantage of this existing cable infrastructure. Where available, cable customers simply order the service and a technician comes out to install a modem designed specifically for cable access to the Internet. The cable modem is a device that connects a local area network to a cable TV line.

Like many cable TV receivers, cable modems are typically part of the Internet cable access and are not purchased and installed by the subscriber. Typically, the cable modem attaches to a standard 10Base-T Ethernet (network) card in the computer by a RJ-45 plug (standard network jack) and attaches to the cable wall outlet using a coaxial cable line.

At top speeds Cable Internet access can download data from 2 to 5 Mbps, with typical rates of speed at 500kbps to 1Mbps. The upload speed is also very high but generally much lower than download rates. Usually uploads speeds range from 128Kbps to 500Kbps. These speeds are comparable with large telephone circuits, yet these speeds are subject to availability, and levels of service provided by the local cable company. Due to its high speed and comparatively low cost, cable modem access to the Internet may appear to be an attractive option.

With these advantages, cable Internet access also comes with some significant downsides, especially for a business. There are a number of challenges faced by the cable industry, including return-path capabilities, customer service issues and standards. Cable modems use “shared” bandwidth for multiple subscribers. This means that unlike the dedicated amount of bandwidth obtained with a telephone circuit, cable bandwidth is divided among numerous other Internet subscribers. Subscribers have reported that performance can vary and, at times, is reduced to that of a standard dial-up modem. While this is an extreme situation, it can be expected that the network performance will deteriorate as local usage increases during peak Internet traffic periods. For example, when many people return home from school or work and begin to use the Internet, during the afternoon and early evening, network performance will degrade. This probably coincides with the peak usage in the dealership as well, compounding the problem. If a cable connection is chosen for a business grade service, make sure that an SLA is available from the provider.

Table 13.5. Cable Modem Internet Access

Key Factors of Cable Modems   

Costs (Approx.)

Equipment/Install Included (standard modems without business-class features).
Circuit$150/month for business grade
Usage FeesNone

Terms

Commitment RequiredMonthly
Quality of Service Service Level Agreement may not match business requirements.

Bandwidth

Capacity Variable capacity is offered up and downstream. Usually 128Kbps upstream and up to 5Mbps downstream.
Consistency Very sporadic. Performance will drop during peak usage hours in afternoon and evenings.
Latency (Delay) Very good but it varies with peak load.
Availability  Limited to parts of major markets in Canada and U.S.

Installation

Complexity Professional installation required for both the circuit and the router.
Support for Business Use Business grade service may not be available from all providers.
Life Span   Emerging technology. Cable and telephone industries merging.
Reuse Combination Possibilities Limited. Cable TV can be used in waiting rooms, lounges, etc.
Other   Concern over security since the LAN is part of larger cable company WAN.

Cable companies tend to market Internet access only to home users. Information is publicly available on methods of attaching cable modems to a LAN. The real roadblock is the level of support from the provider. Cable access targeted for home use does not include the same level of service as offerings designed specifically for a small business. In fact, many cable service providers have a policy against using their service for business access. This should be thoroughly investigated before subscribing to any cable Internet service for business use. If the cable provider has a business services group, talk to them directly to get questions answered. Make sure the Service Level Agreement offered by the cable provider does not prohibit the use of their service for business purposes.

For some business purposes, the concept of a fixed IP or static IP may need to be implemented. This allows for the same external IP address on the cable modem to be maintained at all times. This would be necessary if an external vendor would need to connect to the device for any on-going business needs.

Fiber Optic - Wired Method

In the past few years Fiber Optic Internet access has become more available and affordable for consumers and businesses. This internet access method provides speeds varying from 2 MBPS and up to 1 GBPS. The increasing number of service providers, makes this access method a better alternative to cable, especially if scalibality is a concern.

Although this looks good on paper, there are a few key aspects that one should consider before taking this route. Availabilty is not as good as cable yet, or other broadband access methods; some providers use a mixed of fiber optic and copper cable which creates "bottlenecks" during data transportation, and finally the cost of fiber optic internet access could be higher than other methods.

On the other hand, some of the advantages are: Download and Uploads speeds are usually the same in contrast with cable where the upload spees is considerably lower, bandwidth is very high depending on the service provider.

Table 13.6. Fiber Optic Internet Access

Key Factors o Fiber Optic  

Costs (Approx.)

Equipment/Install Usually Included .
CircuitIt starts at about $80.00 USD/month for business grade
Usage FeesNone

Terms

Commitment RequiredMonthly at least
Quality of Service Service Level Agreement may not match business requirements.

Bandwidth

Capacity Variable capacity is offered. Up and down streams are higher than cable. 2mbps to 1gbps.
Consistency Very good. Depends on service provider
Latency (Delay) Very good but it varies with peak load.
Availability  Limited to parts of major markets in Canada and U.S.

Installation

Complexity Professional installation required for both the circuit and the router.
Support for Business Use Business grade service may not be available from all providers.
Life Span   Emerging technology.
Reuse Combination Possibilities Business telephone service.
Other   Concern over security since the LAN is part of larger cable company WAN.

The factors in the table above are based on the current state of this technology. It is expected that these factors can change rapidly, due to other influences such as advancement in technology, and competition between providers.

Digital Subscriber Line (xDSL) – Wired Method

DSL is a technology for bringing high-bandwidth information to homes and businesses over copper telephone lines. xDSL refers to different variations of DSL, such as Asymmetric Digital Subscriber Line (ADSL), ISDN Digital Subscriber Line (ISDL) , Symmetric Digital Subscriber Line (SDSL), High bit-rate Digital Subscriber Line (HDSL) , and Rate Adaptive Digital Subscriber Line (RADSL). The distance between the dealership and the telephone company’s central office affects service level and availability. DSL offers rates up to 6.1 Mbps (millions of bits) (of a theoretical 8.448Mbps), enabling continuous transmission of full-motion video, audio, and even 3-D effects. More typically, individual connections will provide up to 1.5Mbps to the dealership (downstream) and about 128Kbps from the dealership (upstream). In theory, one DSL line can carry both data and voice signals simultaneously, although deployment of this technology is limited.

DSL has been targeted to replace older technologies and to compete with the cable modem in bringing multimedia and 3-D to homes and small businesses. In markets where DSL is available, costs for older technologies are dropping to stay competitive. Suppliers claim that eventually as much as 80% of the U.S. population will be able to obtain DSL service. However, the OEM’s have determined that less than 25% of dealerships can currently obtain DSL connections. Financial, technical, bureaucratic, and political obstacles have hampered deployment of DSL.

Due to recent bankruptcy filings by DSL providers, dealers should select providers that are financially stable. The failure of several large national DSL providers left large numbers of dealers without Internet service. These dealers have been forced to find new providers on short notice.

Coordination between the local exchange carrier (LEC’s) and ISP providers has also been a problem. ISPs are dependent upon LEC’s to provide physical circuits and to communicate that availability. LEC’s have generally stalled that process in order to keep the circuits for themselves and to protect services like frame relay, which are high-margin product offerings for their operations. Recent Federal Communication Commission (FCC) rulings should help speed that process. Availability of service may be determined by going to www.dslreports.com/prequal. This website is an independently run site that will query the major DSL providers and determine if the dealership location meets the requirements and if service is offered in the area. A positive answer may not be the final word here. Actual availability can only be determined by ordering the circuit. That will cause the providers to measure (called a loop test) the quality of the circuit to verify that DSL service can be provided.

This document will only describe the three most commonly available types of DSL: ADSL, IDSL, and SDSL. Sometimes these are confused with residential-class and business-class product offerings. Some ISPs may even package them that way. Actually, the class of service has less to do with the type of product offered and more to do with the support levels promised and with circuit configuration. Business-level offerings will have a higher quality of service guarantee and they can offer amenities such as a static Internet address, extra email accounts and web server storage. Residential service offers few or no quality-of-service promises and, oftentimes, response to line outages are not handled any faster than those for home telephone circuits. Subscribers have reported circuits that are down as much as 5% of the time. Agreements for residential-class service should be entered into very carefully. Pricing is low and, at times, performance can be very good. However, the low quality of service makes using a residential service a risky business tool. Network performance is affected by the subscription rate. The subscription rate is the number of DSL lines assigned to the CO interface. Carriers refer to that interface as the Digital Subscriber Line Access Multiplexer (DSLAM). The greater the number of customers who share the bandwidth upstream from the DSLAM, the higher the subscription rate is. This means that the network speed can vary and it is not always predictable. Generally, business-level offerings have lower subscription rates than residential offerings.

For some business purposes, the concept of a fixed IP or static IP may need to be implemented. This allows for the same external IP address on the DSL modem to be maintained at all times. This would be necessary if an external vendor would need to connect to the device for any on-going business needs.

In addition, with cable modems, an SLA should be implemented with the DSL provider. This agreement will help in maintaining your business needs as well as your internet connections.

ADSL – Wired Method

Asymmetric Digital Subscriber Line is most often targeted to home and small-business users. ADSL is called “asymmetric” because most of its two-way or duplex bandwidth is devoted to the downstream direction, sending data to the user. Only a small portion of bandwidth is available for upstream or user-interaction messages. This is typically not a problem for web browsing since more bandwidth is required to send web pages down to the user than is required when the user requests the pages. Although greater capacity is available in theory, ADSL service providers in the U.S. often only provide a maximum of 768Kbps downstream and 128Kbps upstream. This is usually done to accommodate subscription levels at the DSLAM.

ADSL is the least expensive (bandwidth/cost) DSL offering. However, support levels for lower-priced offerings are designed for home users. Support may be limited and is not intended for businesses running mission-critical operations. When choosing an ADSL product, make sure to get a business-class Service Level Agreement.

IDSL – Wired Method

ISDN Digital Subscriber Line provides DSL technology over ISDN circuits. Since it requires an ISDN circuit and the speed of the line is about the same, the obvious question is why use an IDSL connection instead of a plain ISDN circuit. The largest benefit of IDSL is that it supports customers located outside the normal distance limitations from the telephone CO. Using IDSL provides the added benefit of having an always-on connection. This eliminates call set-up delays and allows for inbound access. Additionally, a flat-rate billing plan is used instead of per-minute usage fees.

Since both an ISDN circuit and DSL service are required, costs are higher than they would be for either service alone. There also is no natural migration to other DSL services should more bandwidth be required later. That makes IDSL unattractive in areas where other DSL options are available now. However, for users located outside of SDSL or ADSL coverage areas, IDSL may be an alternative.

SDSL – Wired Method

Symmetric Digital Subscriber Line provides equal data transmission rates in both downstream and upstream directions. ISPs normally provide better Service Level Agreements with SDSL offerings than are available with ADSL or IDSL. Additionally, the guaranteed transmission rates are normally higher.

Table 13.7. xDSL Service Comparisons

DSL TypeDescriptionData Transmission Rate Distance Limit (not supported by all providers

ADSL

Asymmetric Digital Subscriber Line (ADSL) 768Kbps-6.1Mbps downstream18,000 ft (1.5Mbps)
 128Kbps-604Kbps upstream16,000ft (2.0Mbps)
  12,000ft (6.3Mbps)
  9,000ft (8.5Mbps)
IDSL Digital Subscriber Line (ISDL) 144Kbps duplex50,000 ft

SDSL

Symmetric Digital Subscriber Line (SDSL) 128Kbps-1.5Mbps duplex18,000 ft (24-guage)
  12,000 ft (26-guage)

Table 13.8. xDSL Internet Access

Key Factors of xDSL   

Costs (Approx.)

Equipment/Install Often included, but some carriers can charge up to $350
Circuit ADSL: $50 – $100/Month, IDSL: $90 – $160/Month ,ISDSL: $100 – $400/Month
Usage Fees Usually none. Plans offer unlimited (or very high) usage limits. Check plan carefully

Terms

Commitment RequiredMonthly
Quality of Service Since it is targeted at business customers, SDSL often has better Service Level Agreement terms. ADSL and IDSL usually offer lower service levels

Bandwidth

Capacity The distance to the central office and the quality of the existing telephone line determines the speed. Maximums are: 768Kbps (ADSL); 144Kbps (IDSL); 1.5Mbps (SDSL)
Consistency Since access at the CO is shared, speed can vary greatly, especially at peak times. Performance is at the mercy of the subscription rate at the DSLAM. Business-class offerings will offer better consistency in part due to lower subscription rates ADSL: Only maximum bandwidths are guaranteed – not the minimum IDSL: The downstream and upstream bandwidths are guaranteed SDSL: The downstream and upstream bandwidths are guaranteed
Latency (Delay) Minimal latency: Always on connection
Availability  Limited to major markets in the United States and Canada. Less than 25% of dealers have coverage today. Circuit availability and speed is dependant upon distance for the CO

Installation

Complexity ISP MUST arrange for circuit install. Router install and configuration will be dealer’s responsibility
Support for Business Use DSL lines do not seem to be repaired with the same urgency as commercial (T1) lines
Life Span   Initial growth has slowed. Important offering for telephone companies
Reuse Combination Possibilities Voice and data may use the same line simultaneously (ADSL and SDSL only).

13.3.2. Non-Wired Methods

Emerging access methods such as wireless and satellite with enhanced technology may be good alternatives when wired methods are unavailable or are highly priced. New-product announcements in both of these areas promise even greater capacity. Since these products have to compete with wired alternatives in order to be truly successful, suppliers are under pressure to deliver them at the lowest possible price. All of the access methods mentioned so far rely on a physical connection with the telephone company or ISP. Wireless connectivity has recently been emerging as an Internet access alternative.

Satellite Technology –Non-wired Method

Satellite technology could be another alternative to consider for dealerships in locations where other access methods may be unavailable or other wise not practical. The current OEM satellite systems were not designed for Internet access and may need to be upgraded or supplemented with additional equipment to perform this functionality. The greatest limitation of using satellite technology for Internet access is the relatively large amount of latency. Latency is the amount of time it takes for data to travel between the user and the satellite and back down to the central ground station and then back again. Using various techniques including IP spoofing, caching, and compression can reduce this problem.

New companies have devised solutions that deal with the latency problem. Many of these companies require new installation of hardware at each location that is using satellite. These solutions have a large benefit to the latency problem, however the price of these solutions are much higher.

Table 13.9. Satellite Internet Access

Key Factors of Satellite   

Costs (Approx.)

Equipment/InstallIncluded
CircuitN/A
Usage Fees$100 - $300 / month

Terms

Commitment Required1-3 years
Quality of Service98% or better

Bandwidth

Capacity Up to 6 Mbps downstream, Up to 256Kbps upstream, Minimum data rates can be guaranteed. Maximum data rates may vary with traffic load
Consistency Geographic location and weather conditions may affect reception
Latency (Delay) Higher than other transport methods (1.5 seconds)
Availability  The service is available everywhere in North America. Global coverage is being investigated

Installation

Complexity Requires professional install for dish and earth station. Configuration of the earth station is required since it acts as router and firewall.
Support for Business Use Business class offerings are becoming available now
Life Span   Emerging now. Life span will depend on market acceptance
Reuse Combination Possibilities Video and IP multicast services may be added
Other   May be a cost effective alternative for the locations where there is no high-speed Internet access available or where wired access is expensive

13.3.3. Wireless Internet Access

Wireless Internet access is an emerging technology that offers an alternative to traditional wired methods when unavailable or not cost effective. Note that this technology has limited availability.

Developments in the use of wireless Internet access technology are bringing new products to the market. These products offer higher-capacity connections at greater ranges and at lower prices than older wireless products do. Businesses are using these products to provide the “last mile” connection from the Internet to the dealership. The wireless connection is used to get data traffic from the dealership directly to an ISP. In some cases, if the ISP will not support the wireless connection, the wireless signal is terminated to a telephone circuit and then sent to the ISP. Wireless is a good option for connecting multiple dealership sites through a wireless LAN. For more information on wireless LANs see the Wireless Networks chapter.

Another comparable wireless frequency technology is Frequency Hopping Spread Spectrum (FHSS). It operates very similarly to Direct Sequence Spread Spectrum (DSSS). In frequency hopping, the signal hops among a variety of frequencies, with the exact sequence of changes (the hopping sequences) known only to the stations participating in the communication. At any instant in time, the signal is being broadcast on only one frequency and the transmission remains on each frequency for only a short time (up to 0.4 seconds) before moving to the next frequency. Thus, interference on a single frequency, or even several frequencies, is not sufficient to disrupt the communication.

In a 2.4GHz FHSS system, the signal hops the entire band using a pseudo-random sequence. All units in a cell must hop at the same time. Each device hops using the same sequence repeatedly, but the devices must be synchronized. This is accomplished by all units knowing the pattern of hopping, the duration of each hop, and the current time of the hop sequence. To prevent interference, multiple FHSS and DSSS systems should not be installed in the same location.

From the viewpoint of the local area network, use of wireless links is transparent. Traffic travels between sites using the same network protocols that wired alternatives use. An extension of the current standard is being developed to support personal devices like cellular telephones or handheld computers.

Table 13.10. Wireless Technology Comparisons

 FHSSDSSS
System Focus Economic SolutionsHigh-performance solutions.
Cost Lower-cost wireless components Higher-cost wireless components. However, total system costs may be less as fewer access points are needed as compared to a similar implementation based on FHSS.
Data Rates Lower per-node bandwidth – the “over-the-air” data rates are about 50% of DSSS systems. Higher per-node bandwidth/“over-the-air” data rates. Able to migrate to 11Mbps solutions in the future.
Range The range is smaller compared to DSSS. Increased range. More suitable for large coverage areas.
Interference Very low, as multiple frequencies and channels are being used. Relatively higher than FHSS as only a single frequency is used.
Scalability Scale up to 10Mbps by adding more access points (maximum of 8 for 1Mbps). Absolute limit of three non-overlapping channels.

Table 13.11. Wireless Internet Access

Key Factors of Wireless Access   

Costs (Approx.)

Equipment/Install$300
Circuit$150/Monthly
Usage FeesNone

Terms

Commitment Required1 year or more
Quality of Service Some guarantees are available. Make sure that SLA covers both wireless transmissions and wired connections from the transmission tower to the Internet.

Bandwidth

Capacity Up to 11Mbps (with greater capacity expected later). Typical offerings are 1.5Mbps. May differ on upstream and downstream volumes.
Consistency Good. Transmissions are unaffected by the weather.
Latency (Delay)Good.
Availability  Currently has limited support from ISPs. Range is good, up to 35 miles from a transmission tower. However, a clear line of sight is required between dealership and the tower.

Installation

Complexity Very complex. Site survey required before install. Professional installation required.
Support for Business Use Business-class offerings are being announced alongside residential offerings.

Life Span

  Emerging now. Market acceptance will determine longevity.
Reuse May be possible to combine with limited amount of voice traffic.