Modem fall into two categories: traffic management, or CDPD. CDPD offers data package applicable to 19.2 Kbps, while the modem, which guides the traffic use on the ceiling for a traffic management limited (14.4 Kbps, depending on the standard). Future 2.5G and 3G networks differ in two distinct ways: traffic rate, from 64 Kbps to 2.4 Mbps later, and all data are either Schnelldurchgeschaltetes or package-based.
CDPD MODEM
Early cellular operators and manufacturers recognized the need for data exchange, and the first modem was the standard modem very similar to that in the houses and in the offices were used.
However, cellular use a valuable, shared commodity - Spectrum. (fixed telephone lines or cables can be shared, but they can always be increased numbers if necessary.) CDPD was created as a digital packet data service via an analog cellular phone: It uses the same analog voice as guides, but with different modulation at the air interface is used. The traffic guidance systems that are not for Fernsprechrufe may be calls for CDPD use. CDPD was the first application of digital data, from the packet data for cellular use, and it is still very much in use today by carriers like AT & T wireless services.
CDPD with analog cellular is fully compatible and is colocated with Ampere systems. Consequently, the analog infrastructure, such as frequency spectrum, cell sites, towers and antennas, are shared. The CDPD network elements cover similar to the analog infrastructure. Analog voice or analog data with a modem, or amps, digital data, a CDPD modem, sharing the same frequency spectrum. External Modem for CDPD communications are most commonly and usually exist as a PCMCIA card for laptop computers, as support for PDA devices, or as an external modem for connection to an analog telephone. Some manufacturers actually include CDPD modem in it with a cellular phone. This is a 2G digital phone "Internet," because all of TDMA and CDMA phones also include compatibility of analog amps and amps to CDPD is worn guides.
Two key design criteria were used to the CDPD protocol to develop. From its inception it was designed to provide TCP / IP, the Internet Protocol and trained to use it transparently to the Internet data. It was also designed to create a network to cover amps and drew benefits from existing infrastructure. These design goals CDPD are very attractive to any institution which manages network amps. This is even more important if a carrier appropriate skills 2.5G or 3G and lacks a competitive disadvantage to be found. CDPD can be any the TDMA or CDMA phone is the Internet, with "data rates of 19.2 Kbps is prepared by it to the TCP / IP in a packet data network instead of a switched through connector is used.
From the end of February 2000, was CDPD into 184 markets in the United States present, the 56 percent of the United States population and 60 World markets cover. As cellular networks, 2.5G and 3G ejaculate, CDPD begins to fade, but as long as it 2G or analog phones are CDPD retains its ability to use. And although it is using SMS for short text ads can compete, it has another advantage-CDPD works on networks with different physical layer. A CDPD modem in a laptop, which uses CDMA, a look at email messages to a phone over the country send the TDMA is used.
TRAFFIC MANAGEMENT MODEM
Many digital phones are advertised, such as Internet-ready and come with a browser or a connectivity kit. The advertising for wireless Internet modem or Internet-ready phones can be very cheat, however. If the indicator is a data rate of 19.2 Kbps mentioned, then there's CDPD. The phone is CDMA or TDMA, but the data is either an internal or external CDPD modem that lead to an analog supply. When a TDMA or CDMA phone data connectivity kit, such as a cable, phone and a laptop and to mention it's not the data rate, or if the phone has an internal browser, the modem is integrated into the phone, and presumably the rate of traffic Leadership, 8 Kbps to 9.6 Kbps and TDMA or CDMA is used for 14.4. The G / M phones have many data capabilities built into the phones used to install it in a laptop through cable modem or inclusively, to include data in the traffic management at 9.6 Kbps to send. In all these cases except CDPD, the connection is still on 2G networks switched through.
A second kind of modem is basically a phone without voice capabilities on a PCMCIA card. There is a modem of this type for each technology. You have an antenna which is integrated into it or by a short cable to an antenna connected. Again if the data rate than 19.2 Kbps is specified, it's CDPD. If the rate is not specified, it's probably a traffic management. Some PCMCIA modem offer a data rate of 56 Kbps to mention radio apparatus in the same sentence. These combine truly modem in one: a land line 56K modem and a wireless modem directs traffic.
With the launch of 2.5G and 3G networks, there are modem, much higher data rates off. They fall into the same two categories: internal to a telephone with a wired connection to a laptop or a PCMCIA card. The GPRS technology is used in Europe but is ejected just like with any new technology, GPRS modem still scarce. The United States will see the following generation modem for CDMA and TDMA phones to the 2002nd The phones use CDMA 1xRTT technology, and the TDMA phones use GPRS. The CDMA Standard1xEV, with data rates up to 2.4 Mbps, is not available until later. Products for W-CDMA will later be available 2002 or 2003.
SHORT MITTEILUNGSDIENST (SMS)
If any application for the killer application could be maintained, "would undoubtedly strong communication on the list in order. Digital cellular brought new data treatment First-generation capabilities to mobile community, as a new service, called SMS or short messaging service in cellular protocols were embedded. All G / M phones support SMS, but not all, TDMA or CDMA phones support SMS completely already. G / M was the first protocol of the SMS to be used, so all have to hook up to the property caught the other protocols work on the enabling of SMS in the network, while more TDMA and CDMA handset the ability to contain an SMS to send. Remember that all-digital phones can receive text messages.
Carriers in Europe reported via SMS as income to 15 percent of income, and even larger percent of profits. Global SMS traffic is at 15 billion ads until December 2001. estimated * While SMS immensely popular in Europe, it is the first step in most conveyor machine communication strategies and is thus the first non-voting-oriented application, the majority of the American consumer experiences. Although mainstream ausstößt and SMS promotions have taken place, widespread adoption is far from complete.
SMS consumer, wireless devices for nonvoice services to use, and it is the linchpin for the next stage of communication, the elements other than simple text, graphics, sound, and contains specific formatting. Before the United States to the same customers can enjoy widespread use, the G / M users, however, some problems need to be resolved.
Not all SMS messaging is created equal. The number of letters, the SMS can be sent varies by protocol and promotional machine. Usually sends G / M 160 letters, 150 letters sent TDMA, and CDMA can be up to about 200 touch. Some phones receive only and can not send SMS. The turn and the interconnectivity of SMS is a major challenge for significant growth in SMS traffic. CDMA users can not send the SMS TDMA users.
A second problem area is calculated. Counting fees, the adoption of SMS, because most consumers of the need to SMS are unsure and do not have reference for consumption. Fees may be counting trays in the 'Ad, per "" SMS's, "or released. Most carrier SMS encounter with a period of free SMS ads before the primary offer of a tub SMS ads (200-800) for $ 4-8 per month to move.
Speed and latency is another potential problem area in the United States. Before this was a problem in Europe for six years, however, because a due SMS technology in Europe, is latency "out" has been fine-tuned. A typical SMS ad is very small, fast, than 5 seconds from send to receive. Sometimes in the United States, however, the SMS traffic is so heavy (holidays, etc..) That is delayed is hours as measured in seconds. SMS loses value quickly, while the latency increased. Engine control latency by adding processing power of the short message service center (SMSC).
Any technology-based service such as cellular or the Internet is constantly developing into something different and hopefully better. SMS is no different, it migrates to the newer versions, such as intelligent messaging, instant messaging, multimedia messaging and enhanced SMS (EMS or E-SMS). SMS is not recorded on tape package delivery and low-bandwidth transmission mode characterized by the highly efficient means for transferring the short shocks of data results. Initial applications of SMS focused on eliminating alphanumeric pagers by mutual universal messaging and communication services, primarily for voice mail enabled. As technology and networks evolved, a variety of services, including email, fax and pagination integration, interactive banking, information services like stock quotes, and integration with Internet-based applications has been introduced. Wireless data applications include downloading of the maps of the subscriber identity module (SIM) for activation, the liabilities and profile-editing purposes, wireless outlets (position) and other start-service applications such as automatic Meßinstrumentmesswert, Remote, and location-based services. Additionally drove integration with the Internet, the development of network-based messaging and other interactive applications such as instant messaging, games and chat to.
It seems that mobile messaging is a valuable application that is popular in business and consumer sectors in the win. Mobile messaging services continue in the future networks continues, and multimedia messaging is emerging as more bandwidth is available.
GENERAL PACKET RADIO SERVICE (GPRS)
General Packet Radio Service (GPRS) is a G / F Phase 2 + carrier service. He is the first true step forward in the packet data service since CDPD, and is the first packet data service in wireless digital networks. He will z.Z. in Europe in the G / M networks expelled, but a general starting upproblem its growth deficiency of equipment suspended! GPRS handset are still scarce. This is a recurring nightmare for operators of all new technologies: when WAP was introduced, there is a lack of listeners and the content was.
This results from the classic "chicken and egg" syndrome. Because GPRS costs more with the hand made order in small quantities to form, are the consumer prices higher. With low sales figures manufacturers produce small quantities of the product. The ramp-up to the higher volume of production takes time, but it happens, from which you can be sure. GPRS is the backbone of G / M and TDMA networks for wireless packet data. Radio equipment will be moving through all the stations divided, and GPRS analyzed from those resources each user as required, because the Internet, browse normally, data shows the impact instead of steady streams is transmitted. This causes greater efficiency in network capacity management: The data rates, which Kbps as high as 115, can be achieved.
Unlike SMS messaging GPRS was not originally a part of the G / M (or TDMA) network. For this reason, some new network elements to the G / M architecture are introduced, and some mobility management functions need to be changed. Unlike CDPD GPRS but is testing a data sheet within the standard G / M of this infrastructure by adding additional elements. Packet data through a GPRS network does not use switched through web resources. One of these additional network elements will support the zero point of entry-GPRS (GGSN) called. In essence this is a packet router with some mobility management functions. It connects to the G / M network and the external packet network by means of Zero standard interfaces.
The second new element in the function is very similar, except that it connects directly to the low-control station at (BSC). The support of the zero-wrapping GPRS (SGSN) is responsible for the handling of packet data to and from the mobile unit is responsible.
BT Cellnet began to GPRS network to the mobile phone users in Europe in 2001 offering. New tests of those services but do not have many clients impressed. Actual data rates do not have expectations, but it is a new service and there is much "fine tuning" to the system over the next few months.
If GPRS its promise of higher data rates are met, many new applications possible over-G / M and TDMA networks. GPRS enables fully mobile Internet applications to the network are similar, on a desk calculator grazes. Applications include file transfer that surfing the net and of course, email with attachments.
As with any new technology, GPRS has little negative impact on a network. Not only are data resources, they are shared with voice-operating funds for any given cell site is divided between the need to voice user guides and GPRS users shared. If all the guides in language use and file transfers at all packet data Tours take place, there is no more capacity for this particular cell site, until someone stops, some of the equipment to be used. Dynamic allocation of funds can only do so much.
Author : Steve Galloway