Wireless data protocol WAP(Wireless Application Protocol) is used to develop Internet pages specifically designed for display on mobile devices of cellular network subscribers. The prerequisites for the creation of the WAP protocol arose with the advent of the possibility of exchanging information in mobile networks and subscriber access to the Internet. At the first stage, there were two main problems that made it difficult to surf the web using a mobile phone. Firstly, the first mobile terminals of the 90s were equipped with low-resolution monochrome screens, which made displaying traditional Internet pages written in HTML (HyperText Markup Language) very problematic. Secondly, pages originally designed for viewing on personal computers were quite large in size (sometimes > 100 kB), which made them very slow to load over low-speed cellular data links. Thus, WAP was designed to optimize web pages and solve the above-mentioned problems.

A specially created standardization organization took on the development of the WAP protocol in 1997. WAP forum, which included the main manufacturers of telecommunications equipment. Their main goal was to combine several disparate wireless data protocols into one. As a result of their work, the first version of the WAP standard appeared in 1998. Then, two more standards were released at intervals of one year. WAP v1.1 And WAP v1.2. In 2002, the WAP Forum organization joined the association of operators and organizations in the field of mobile technologies OMA (Open Mobile Alliance). The merger was followed by a new protocol release WAP v2.0, which included significant improvements.

In general, the WAP protocol is a set of protocols and technologies that ensures the creation and transmission of web pages to subscriber terminals and corresponds to OSI levels 2 to 6:

• Executive level WAE (Wireless Application Environment).
• Session layer WSP (Wireless Session Protocol).
• Transport layer WTP (Wireless Transaction Protocol).
• Network layer WTLS (Wireless Transport Layer Security).
• Data link layer WDP (Wireless Datagram Protocol).

The WAE layer defines Hypertext Markup Language, which is one of the defining features of WAP. The first version of WAP used WML (Wireless Markup Language), and the release of WAP v2 used XHTML (eXtensible HyperText Markup Language), which allows you to create web pages that can easily be opened both on mobile terminals and on desktop computers without loss of data. quality, content or functionality.

Subsequently, the WAP protocol did not become as widespread as expected at the beginning of its development. This is primarily due to the rapid development of cell phone and data technologies, which have meant that modern smartphones can handle traditional web pages built for computers as easily as PCs themselves. However, the WAP standard has still not lost its relevance - many website developers create separate WAP versions of websites specifically for subscribers with outdated mobile phones. In addition, the release of WAP v2.0 gave new impetus to the further development of the wireless data transfer protocol. True, web developers are not yet very active in creating pages in XHTML.

Something about WAP

Today, even in Russia, you won’t surprise anyone with a cell phone. Both businessmen and students have pipes. However, if the latter use the capabilities of the handset by 50 - 60 percent, and maybe less, then business people, as they say, take everything from the phone. Or almost everything.

Today, the capabilities of cell phones are simply enormous, and they are only increasing every day. And if you consider that companies producing cell phones throw more than one new product onto the market per month, it is almost impossible to keep track of all the innovations. Yes, this is not necessary. It is enough to learn about truly global and promising innovations in time.

What am I getting at? Today, most of us (and the overwhelming majority) have already realized that life without the Internet is not life at all. And so, existence...

Rest, work - everything is connected to the Internet. It’s just a pity that you can’t use it during numerous and not so numerous trips and business trips. Although... You can carry a laptop with you...

It could be simpler. You can simply buy a cell phone that supports WAP function. And from now on you will not have any problems. It seems...

WAP (Wireless Application Protocol)

There was, and still is, a lot of noise around this technology. Just like it once was around the Iridium satellite communications system. Only we know what happened to this project...

I don't want to say that WAP will face the same fate. However, if earlier information about this system was spoken loudly, beautifully and only good things, today you can increasingly hear loud, but not so beautiful words that WAP generally has more disadvantages than advantages. But first things first. Maybe someone doesn’t even understand what we’re talking about here...

So, what is WAP? This is the name of the protocol that allows you to access the Internet using only a mobile phone, without the participation of a modem, computer or similar devices. Thus, WAP combines two of the fastest growing and developing industries - cellular communications and the Internet. This is why there is so much buzz around WAP. In addition, previous attempts have been made to create a similar system, but they all ended in failure. WAP has every chance to correct the situation.

It would seem like a win-win option. However, there is a nuance. Through WAP you can visit not just Internet sites, but only WAP pages. In principle, they are no different from ordinary ones, the only problem is that there are very few such WAP pages. In the world in general, and even more so in Russia.

It is inconvenient to open ordinary HTTP pages through a cell phone because such pages have large headers (remember the size of the display of your cell phone), the lack of a compression protocol, too much service information, and much more. WAP pages, on the other hand, use a binary standard that allows data packets to be compressed, they are less saturated with graphic information, etc.

And by the way. Speaking about WAP, one cannot fail to mention such a protocol as GPRS. We will have a separate conversation about it, but it’s simply impossible not to mention it now...

The GPRS (General Packet Radio Service) protocol is a protocol that is used for data transmission in GSM networks. This allows GSM networks to be compatible with...that's right, the Internet. The GPRS protocol uses packet technology to efficiently transmit bursty traffic. This protocol supports transfer rates from 9.6 Kb/s to more than 150 Kb/s per user.

In our country, WAP telephony services are provided by Mobile Telesystems and Beeline in Moscow, and St. Petersburg North-West GSM.

True, today many Internet sites create special WAP versions of their pages for their clients. In particular, Yahoo did this not so long ago, providing users with the opportunity to receive various information that is well adapted to the small screens of cell phones, and there is also access to e-mail.

Among the Russian WAP sites, we can note the sites of the operators themselves. For example, the MTS company website allows you to send e-mail from it, find out the weather forecast, and even get acquainted with ordinary Web pages. Moreover, this is very simple to do - you enter the site address without using a browser, but in a special form. On the site... Soon it will be possible not only to send mail, but also to receive it.

“NWGSM”, and the company “Infoart”, and some others have their own WAP site. And of course, this is not enough. In addition to information about the weather, traffic jams and available plane tickets, sometimes you urgently need other, more informative and voluminous information. But the appearance of such sites, and in large numbers, is still a long way off. However, most likely they will still appear... Although many argue that WAP has no future. Such pessimists justify their opinion by the fact that, firstly, this project is not finished yet, is imperfect, and is unlikely to ever work at full capacity, and secondly, using WAP is very expensive. And in this they are partly right. Indeed, access to the Internet via a WAP browser costs from 5 to 30 cents per minute. And this is a bit expensive even for those who can afford expensive handsets that support WAP. Speaking of birds.

Until recently, there were only one or two cell phones that support WAP. However, mobile phone companies have apparently conspired to completely eliminate at least this problem with WAP technology. Today, almost every new product in the field of cell phones is equipped with a WAP browser, that is, it is capable of working with the WAP protocol. Many of these new products have already reached Russia, although we already had such phones before. Among the phones that have reached or almost reached our country are Nokia 7110, Nokia 6210, Motorola TP P7389, Ericsson R320, Ericsson R380, Bosch 1886 and some others...

However, you should remember (or know) that the WAP protocol comes in two types - versions 1.0 and 1.1. Version 1.0. has long been outdated and is no longer used practically anywhere, including in our country. Therefore, when purchasing a cell phone that can work with WAP, you must find out which version of this protocol a particular phone supports. For example, many owners of a Siemens S25 phone once discovered that their phone, although proudly called “WAP-supporting,” did not support exactly what it needed. Namely - standard 1.0. Sad for the owners. Lesson for potential buyers...

To enjoy all the delights of WAP, you will have to pore over your cell phone for more than one hour - you need to configure more than 20 parameters... And this is also one of the disadvantages of WAP. Although, in fact, with a certain skill, all settings, which are 8-10 parameters, can be completed in 10-20 minutes even by a non-specialist.

Since we're talking about shortcomings again, let's name one more. True, this is rather a problem for Web masters, since the content of sites has to be rewritten in the WML (Wireless Markup Language) format, which allows you to display pages on the same small displays. Moreover, for 4-line displays you need one option, and for 8-line displays - another...

In general, there is plenty of criticism. The most unpleasant thing is that it is also heard among the creators of this technology themselves. The so-called WAP Forum, which manages the project and monitors its development, unexpectedly received critics within its own ranks. In particular, David Rensin, technical director of Aether Systems, which develops Internet access infrastructure for portable devices, spoke at the Mobile Insights conference about the “death of WAP.” This statement was so unexpected that many almost panicked. Of course, you shouldn’t take such statements as prophetic, but it’s certainly worth thinking about the urgency of buying a cell phone equipped with a WAP browser...

However, there is also a rather neutral assumption. They say that WAP is a transitional standard. That he will go into oblivion, and on his “remains” the final version of the project for connecting the Internet and cell phones will arise. But these are just assumptions.

To brighten up the picture, let’s mention that. that WAP is compatible with a large number of transport protocols and with such promising technologies as Bluetooth. In addition, technologies that complement WAP are already being developed today. For example, Aether's ScoutWeb technology complements WAP to adapt Web sites to PDAs (personal digital assistants) and cell phones...

In general, analysts (those who are optimists) predict that by 2002 all cordless phones will become WAP compatible. And that in general the number of WAP Internet users will be 20 - 30 percent of all mobile communications users... And yet there is no point in “burying” personal computers. No one will use a cell phone to access the Internet all the time, no matter how cheap the service becomes. Why? At least because of the same small screen...

Most likely, there won’t be a large-scale breakthrough right away. More precisely, it wasn’t. There are too few WAP sites, too few phones (compared to simple cell phones), it costs too much, too... too many of these "too"...

In general, final conclusions about WAP communications will have to wait at least another year. In the meantime, WAP technology has been and remains more of a very expensive entertainment than a work tool. The exception is those specialists who need only textual, only brief and only urgent information. These could be exchange rates or, for example, securities quotes. But the number of such people in need is so small that, I repeat, it is still quite early to talk about the mass use of WAP...

WAP? What it is?

GPRS

4.1 GPRS

One of the significant disadvantages of GSM cellular networks today is the low data transfer speed (maximum 9.6 kbit/s). And the organization of this process itself is far from perfect - one voice channel is allocated to the subscriber for data transmission, and billing is carried out based on the connection time (and at tariffs that differ little from voice ones).

GPRS (General Packet Radio Service) was developed for high-speed data transmission via existing GSM networks. It should be noted that in addition to increasing the speed (the maximum is 171.2 kbit/s, but more on that below), the new system assumes a different payment scheme for data transfer services - when using GPRS, calculations will be made in proportion to the volume of information transferred, and not the time spent online. In addition, the introduction of GPRS will contribute to a more economical and rational distribution of radio frequency resources: without going into too much technical detail, we can say that data “packets” are supposed to be transmitted simultaneously over many channels (it is in the simultaneous use of several channels that the speed gain lies) in pauses between speech transmissions. And only during pauses - voice traffic has unconditional priority over data, so the speed of information transfer is determined not only by the capabilities of the network and subscriber equipment, but also by the network load. I would like to emphasize that in GPRS not a single channel is dedicated entirely to data transmission - and this is the main qualitative difference between the new technology and those used today. Just imagine - you can always have a green ICQ daisy on your laptop without loading the network, and pay in proportion to the volume of messages received and sent

Of course, the GPRS developers made every effort to ensure that installing a new system “on top” of existing GSM networks would be as less burdensome (and costly, which is important) as possible for operators. Let's take a closer look at what new blocks and connections appear in the overall architecture of the GSM cellular communication system with the introduction of GPRS, and then discuss user equipment capable of working with high-speed packet data transfer.

GPRS from inside.

Refinement of the GSM network to provide high-speed GPRS data transmission services can be divided into two forms - software and hardware. If we talk about software, it needs to be replaced or updated almost everywhere - from HLR-VLR registries to BTS base stations. In particular, a multi-user access mode to temporary frames of GSM channels is being introduced, and in HLR, for example, a new parameter Mobile Station Multislot Capability appears (the number of channels that a subscriber’s mobile phone can simultaneously work with, but more on that below).

The core of the GPRS system (GPRS Core Network) consists (Fig. 1) of two main blocks - SGSN (Serving GPRS Support Node - GPRS support node) and GGPRS (Gateway GPRS Support Node - GPRS gateway node). Let's look at their functions in more detail.

The SGSN is, roughly speaking, the brain of the system in question. In some ways, SGSN can be called an analogue of MSC - a GSM network switch. SGSN controls the delivery of data packets to users, interacts with the register of its own subscribers of the HLR network, checking whether the services requested by users are allowed, monitors online users, organizes registration of subscribers who have newly “appeared” in the network coverage area, etc. Just like MSC, SGSN, there may be more than one in the system - in this case, each node is responsible for its own section of the network. For example, SGSN manufactured by Motorola has the following characteristics: each node supports transmission of up to 2000 packets per second, simultaneously controls up to 10,000 online users. In total, the system can have up to 18 Motorola SGSNs.

The purpose of GGSN can be understood from its name - roughly speaking, it is a gateway between the cellular network (or rather, the part of it for transmitting GPRS data) and external information highways (Internet, corporate intranet networks, other GPRS systems, and so on). The main task of the GGSN is thus to route data going to and from the subscriber through the SGSN. Secondary functions of GGSN are data addressing, dynamic issuance of IP addresses, as well as tracking information about external networks and its own subscribers (including service tariffs).

I note that the GPRS system has good scalability - when new subscribers appear, the operator can increase the number of SGSNs, and when the total traffic escalates, add new GGSNs to the system. Within the core of the GPRS system (between SGSN and GGSN), data is transmitted using a special GTP tunnel protocol (GPRS Tunneling Protocol).

Another component of the GPRS system is the PCU (Packet Control Unit). The PCU interfaces with the BSC base station controller and is responsible for routing data traffic directly from the BSC to the SGSN.

In the future (when the system is oriented towards the mobile Internet), it is possible to add a special node - IGSN (Internet GPRS Support Node - Internet support node).

OMC-R/G (Operation and Maintenance Center - Radio/GSN - control and maintenance center for the radio/GPRS node: not shown in Fig. 1) is responsible for managing and monitoring the GPRS system. This is, so to speak, the interface between the system and its operating personnel.

Before starting to work with GPRS, the mobile station, as in the usual case of voice transmission, must register in the system. As already mentioned, the registration (or, more precisely, the “attachment” to the network) of users is handled by the SGSN. If all procedures are successfully completed (checking the availability of the requested service and copying the necessary user data from the HLR to the SGSN), the subscriber is issued a P-TMSI (Packet Temporary Mobile Subscriber Identity) similar to the TMSI that is assigned to the mobile phone for voice transmission (by the way, if the subscriber terminal belongs to class A (see below), then both TMSI and P-TMSI are allocated to it during registration).

To quickly route information to a mobile subscriber, the GPRS system needs data about its location relative to the network, and with greater accuracy than in the case of voice traffic transmission (let me remind you that HLR and VLR store the number of the Location Area (LA) in which the subscriber is located). But imagine how the service traffic on the cellular network and the energy consumption of a mobile device will increase if the phone informs the system every time it moves from one cell to another! In order to find a reasonable compromise between the volume of signaling traffic in the GPRS network and the need to know the subscriber’s location with high accuracy, it is customary to divide terminals into three classes:

• IDLE (idle). The phone is switched off or out of network coverage. Obviously, the system does not track the movement of such subscribers.
• STANDBY (standby mode). The device is registered (attached) in the GPRS system, but has not been transmitting data for a long time (determined by a special timer). The location of STANDBY subscribers is known accurate to RA (Routing Area). RA is smaller than LA (each LA is divided into several RAs, but nevertheless, RA is larger than a cell and consists of several unit cells).
• READY (readiness). The subscriber terminal is registered in the system and is in active operation. The coordinates of phones in READY mode are known to the system (or, more precisely, SGSN) accurate to the cell.

According to this ideology, terminals in STANDBY mode, when moving from one RA to another, send a special signal to the SGSN to change the routing area (routing area update request). If the new and old RA are controlled by the same SGSN, then changing the RA only leads to an adjustment of the entry in the SGSN. If the subscriber moves into the coverage area of ​​a new SGSN, then the new SGSN requests information about the user from the old one, and the MSC, VLR, HLR and the GGSNs involved are notified of the change in SGSN. When a GPRS phone moves to another LA, the SGSN sends a message to the corresponding VLR to change the subscriber's location record.

The situation with data routing in the case of roaming GPRS subscriber is interesting. In this case, two options, or, more correctly, scenarios, are possible. SGSN in both cases is used as a guest (VSGSN - Visited SGSN), but GGSN can be used either as a guest (VGGSN - Visited GGSN) or home (HGGSN - Home GGSN). In the latter case, a GPRS backbone (InterPLMN GPRS BackBone - GPRS line between different mobile networks) must exist between the home and guest operators to transmit traffic between the HGGSN and the mobile subscriber. In addition, there is a need for a BG (Border Gateway) on both sides in order to ensure the protection of networks from external attacks.

It is worth noting such an important parameter as QoS (Quality of Service). Obviously, real-time video conferencing and sending an email have different requirements, such as delays in the path of data packets. Therefore, in GPRS there are several QoS classes, divided according to the following criteria:

• the required priority (there is high, medium and low data priority);
• reliability (divided into three classes according to the number of possible errors of various kinds, lost packets, etc.);
• delays (information delays outside the GPRS network are not taken into account);
• quantitative characteristics (peak and average speed);

The QoS class is selected individually for each new data transfer session.

In addition to QoS, the characteristics of a data transmission session include the protocol type (PDP type - Packet Data Protocol type); PDP address issued to the mobile station (address issuance can be either static or dynamic); as well as the GGSN address with which you are working. The session “profile” (in English literature the designation “PDP context” is accepted) is recorded in the phone, as well as in the SGSN and GGSN serving it. Several data transfer profiles can be supported simultaneously for each user.

Generally speaking, packet data transfer provides two modes of “connections”:

• PTP (Point-To-Point - point-to-point);
• PTM (Point-To-Multipoint - point-to-dot).
• The RTM broadcast mode is in turn divided into two classes:
• PTM-M (PTM-Multicast) - transfer of necessary information to all users located in a certain geographical area;
• PTM-G (PTM-Group Call) - data is sent to a specific group of users.

Support for PTM multipoint transmission is expected in future GPRS specifications.

GPRS outside - subscriber devices.

Let's now talk about GPRS client equipment. Unfortunately or fortunately, to work with the packet data transmission system you need to have a special phone compatible with GPRS. More strictly speaking, GPRS terminals are divided into three classes:

• devices class A capable of simultaneously working with both voice and data transmission (technically speaking, they have the ability to operate in both circuit switched and packet switched modes). Let me emphasize that we are talking about simultaneous work in different modes);
• devices class B can carry out either voice or data transmission, but not simultaneously;
• devices class C Only support data transmission and cannot be used for voice communication. As a rule, these are various kinds of computer boards to provide wireless access to data.

It should be noted that the maximum data transfer rate is determined, first of all, by the number of channels with which the subscriber terminal can simultaneously operate. One channel provides data transmission at speeds up to 13.4 kbit/s.

The last thing you need to do before connecting to the Internet is to order the “Data and Fax Transfer” service from your mobile operator. Most often, this is enough to simply call the operator service. Then click on the “Internet” icon and the computer will begin to interact with the cell phone via the modem. After a few seconds, you will see the words “Data” on the display, and the browser’s home page will load on the pickpocket’s screen. Everything happens quite quickly. Now you can surf the Internet. But do not forget that payment will take minutes.

WAP protocol

Wireless Application Protocol (WAP) is a protocol for wireless access to information and service resources of the global Internet directly from mobile phones. The creation of the WAP specification is carried out by the WAP Forum organization (http://www.wapforum.org/), which includes all major participants in the telecommunications services market.

The main advantage of WAP is that to work on the Internet, the subscriber does not need additional devices - a computer and a modem; one mobile device with WAP support is enough. This is not the first attempt to give users access to the World Wide Web using mobile phones, but perhaps the most successful. This protocol describes the form in which data must be presented on the Internet so that a mobile device can access it. This condition initially imposes a limit on the number of resources available to users, since it is not possible to view regular HTML pages. This is primarily due to the imperfection of the displays of portable devices; in most cases they are still not color and have a low resolution. To display a regular page with text, you would have to scroll it on the screen of such a display many times in both directions, which, of course, is inconvenient. Therefore, a special language was created, similar to html and describing how data will be displayed on the display of a mobile device. This language is called wml.

In addition to support from Internet resources, support from the cellular operator is also required. Thus, this protocol describes the interaction of mobile devices, cellular operator equipment and pages with information on the network. To view WAP pages, it is absolutely not necessary to have a phone that supports this protocol. To do this, just use an emulator, for example, Wapalizer. You can also install an emulator program on your computer, for example, WinWap.
In most cases, WAP pages are short summaries with important information, which is due to the high cost of transmitting information through cellular communication systems. Therefore, transmitting graphics and multimedia is quite expensive. The GPRS standard is used for this (see below)

With the advent of the WAP protocol, subscribers of cellular communication networks have the opportunity to use a variety of services on special WAP sites; e-mail, WAP stores, booking tickets and hotel rooms, access to your bank account, information channels (news, weather forecast, exchange rates, theater repertoire, etc.). And what is especially important is that the subscriber maintains mobility within the coverage area of ​​his network.

WAP sites are located on web servers and are presented in a special WML (Wireless Markup Language) format. This markup language is specially adapted to the capabilities of a mobile phone - two-color graphics, a small screen and small memory. MTC was one of the first companies on the Russian Internet to create its own WAP site. It contains information about the company, a brief description of all telephone models sold by the company's offices, a description of services, addresses of service centers, etc. You can also send an e-mail and take part in a WAP chat.

In order to use the WAP protocol in the MTC network, a subscriber only needs to have the “Data Transfer” service, which is added to an existing number and is part of the “Mobile Office”. Of course, your device must support this protocol. Here is a list of some cell phone models that support WAP1.1 (Nokia 7110, Ericsson R320s, Motorola P7389 Time Port, Siemens S35i, Siemens C35i). You can read more about this on the MTS website.

It should also be noted that there are special WAP - Gateways (WAP gateways) that translate a request from a mobile device into a standard HTTP form. Here is a list of some WAP gateways:
192.36.156.23; 212.4.198.194 (reg.); 212.1.130.132 (waphq:waphq); 195.102.185.138; 212.4.198.194 (:demo); 192.168.210.1 (T99:T99); 194.154.120.10 ( [email protected]:wapme); 209.208.254.180.

WAP technology has good prospects since the development committee includes such companies as: Alcatel, Ericsson, Matsushita, Motorola, Nokia, Philips, Qualcomm, Samsung, Intel, NEC, Siemens, Fujitsu, IBM, Psion Software, AT&T Wireless Services, BellSouth Cellular Corporation, Sonera, Telenor, Telstra, T-Mobil, Vodafone, BT Cellnet, Sprint PCS, Swisscom, Telia Mobile.

NOKIA predicts that in 2003 there will be more than 1 billion digital mobile phones and new WAP-optimized devices on the airwaves. Ericsson estimates that in 2001, about 50% of all mobile subscribers will use WAP-based phones.

GPRS technology

In the near future, the Moscow company Mobile TeleSystems plans to begin testing the technology of packet data transmission GPRS (General Packet Radio Service). This is the beginning of the path to 3rd generation network services, where it will be possible to transfer almost any information - from voice to image - directly to a mobile phone.

The advantages of using this technology are, for example, that subscribers using mobile Internet access will pay not for airtime (as now), but for the volume of transmitted information. Suppose you are waiting for an e-mail. To find out if the long-awaited message has arrived, you need to connect to the Internet and check your mailbox. Regardless of whether there was a letter or not, you will pay for the time on the line. In the case of GPRS, the phone is constantly in touch, and as soon as an email message arrives, it is immediately delivered to you. In this case, you pay only for the volume of transmitted information.

In addition, GPRS will increase the data transfer speed. Today GSM provides data transfer speeds of up to 9600bps. The first phase of GPRS, which is now being introduced worldwide, will increase speeds to 14400bps. Then an increase to 50kbit/s, and in the future - to 116kbit/s. However, it is not yet known when phones with GPRS support will appear. The equipment of cellular operators provides all the modes necessary for GPRS, but these capabilities cannot yet be fully realized precisely because of the lack of equipment for company clients.

Today, in the age of technological progress, you will no longer surprise anyone with a cell phone, much less the Internet. Life without the latter is not life at all, just existence. Rest, work - everything is connected to the Internet. Moreover, you want to be able to use it always and everywhere. This is feasible: WAP technology will come to the rescue, support for which is implemented in almost all modern mobile phones.

I think with my introduction I didn’t discover anything new for most users, but wait: do you know how and how WAP 1.2.1 differs from 2.0? I'm guessing not. Therefore, it is the WAP protocol and the differences between its versions that will be discussed in this chapter.

Almost a year later, in June 1999, a new version was presented to the public - WAP v1.1. It fixed a large number of “bugs”, so there was no backward compatibility with the previous edition of the protocol. Among the main innovations is the WTA (Wireless Telephone Application) function, which allows you to organize session continuity even during a phone call, and support for a secure Internet connection WTLS (Wireless Transport Layer Security). When the first devices with version 1.1 appeared, something apparently didn’t work out and the popularity of WAP fell sharply.

In the summer of 2000, WAP v1.2 and its subtype WAP v1.2.1 were released. They now have support for displaying grayscale on the display, authorization using a digital signature, and so-called push technology. However, WAP 1.2 also had many shortcomings.

The global revolution took place in January 2002 - WAP v2.0 was released.

The developers of the second version of the protocol took into account the mistakes of the past and, without unnecessary fuss, prepared a radically new standard that takes into account modern realities and which is far from all its predecessors of the same type.

The transition to WAP 2.0 is a conceptually new solution, which, together with the GPRS service, can last quite a long time compared to previous versions. But what did the protocol developers come up with that was so innovative?

As you know, in order to display a website on a mobile phone screen, it must be written in a special language, WML. which in its first edition had very little in common with web-native HTML. Therefore, previously, from a cell phone it was possible to view only sites specially created for this purpose - the so-called WAP versions. This limitation, in fact, forced us to reinvent the wheel again and create our own Internet in mobile devices.

In the second edition of the protocol, the developers corrected this serious drawback: WML 2 appeared, which is based on the XHTML language (Extensible Hypertext Markup Language). In essence, this is the same HTML, that is, the language used to describe, mark up the text content and page format of the regular Internet, only written in accordance with the syntactic rules of XML - Extensible Markup Language. Support for CSS style sheets (Cascade Style Sheet) was also provided. Thus, WAP 2.0 supports open standards, which in turn are compatible with most browsers on PCs.

I can’t ignore the noticeable leap in the improvement of push technology, when using which the server itself can send information of interest to you to your phone, be it news, newsletters or something else. You don't have to look far for an example. Let's say you subscribe to stock exchange updates; in the classic version, your phone will have to periodically request data from the server in order to immediately report it when new information appears. Having push technology, the server itself sends you updates when they arrive. The advantages are obvious: fast, convenient and, due to one-way data transfer, economical. True, to use push technology, it is necessary to have a special rgox server on the side of the service provider (operator) providing the content.

In addition, features such as MMS (multimedia messaging) and SyncML (data synchronization) were integrated into the standard specification. Now the browser supports not just sending MMS messages, but any manipulations possible in this service. There was also support for vCard and vCalendar formats, which are standard in organizers and phone books, which led to the use of SyncML in the following way: for example, your manager adds an unscheduled meeting to his work schedule, synchronizing his phone with the database over the network. By repeating the same thing, only without the first action, you can easily find out the plan of the working day. And this is not all the possibilities of using data synchronization!

Interaction of a mobile phone with various external devices (GPS sensor, digital camera) is ensured using the EF interface (External Functionality). Personally, I haven’t seen this, but since it’s stated...

In the latest edition of WAP, a lot of attention is paid to the issue of security. Currently, secure operation requires protection using at least 128-bit encryption at the transport layer and also support for a public key infrastructure. The secure connection between the WAP gateway and the Internet content server is provided by SSL (Secure Sockets Layer) or TLS (Transport Layer Security) protocols, which generally stands for secure transport layer. In the area between the mobile device and the WAP gateway, the WTLS (Wireless Transport Layer Security) standard is used, which ensures the confidentiality of transmitted data. It uses certification based on the aforementioned public key infrastructure (PKI), allowing WAP gateways and clients to authenticate each other and exchange data encrypted with digital signatures. The only unprotected place in this situation is the WAP gateway itself.

Let me explain: the owner of the gateway has access to all traffic used by subscribers. A “unique” WIM module helps combat this bad phenomenon. This is a microprocessor card introduced into WAP to radically solve the issue of transaction security and their authorization using a digital signature.

Let us highlight two main tasks of the module. The first is protection at the WTLS protocol level between the gateway server and the cell phone. Or more precisely, mutual identification and increasing the crypto-resistance of information. The processing algorithm is stored in WIM memory. Considering the fact that a certain level of security is provided by the SIM card, the WIM module creates a simply insurmountable barrier, since it uses an encryption algorithm based on elliptic curves (one of the public key technologies). The second security function is support for a digital signature in combination with a method to prevent transaction refusal, that is, if a subscriber orders a product, he will no longer be able to refuse to pay for it. Moreover, the digital signature can be combined with another identifier, for example with a PIN code.

How will the WIM module be implemented? As an option, it is proposed to install it in a cell phone in the form of an additional card. However, it is better to integrate the WIM module into the same board as the SIM, but program them separately from each other. For example, the first one is with the operator, and the second one is in the bank where the subscriber’s account is located.

Table 9.1 Functionality of different WAP versions

Many will ask where all these functions come from; I knew nothing about them and had never even heard of them. That's right, what the developer announces is not always implemented by the manufacturer in its solutions - this is a fact. At the same time, it seems to me that the hour is far from certain when every user will be able to test all the above-described functions in practice!

People often confuse the purpose of WAP and GPRS technologies. Let's be clear. If you read the previous chapter, then you know that GPRS is a modern data transmission technology in GSM networks, replacing the outdated data transmission technology over voice channels (CSD). WAP technology, using the GPRS or CSD protocols to transmit information, allows you to view special WAP sites on your mobile phone screen, optimized for display on small screens of mobile devices and transmission over low-bandwidth data channels. The main advantage of WAP is that you do not need to use additional devices to surf the Internet - a mobile phone that supports this technology is enough; the information will be displayed directly on the mobile screen. Thus, sitting in a cafe, bar, on a bench in a public garden, or walking down the street, you can access Internet resources. To do this, it is enough to have a mobile phone with support for WAP technology, connected to the network of the operator providing this service.

The abbreviation WAP stands for Wireless Application Protocol - wireless access protocol. This protocol allows you to use Internet resources only through a mobile phone, without resorting to a computer. Essentially, it is a technical standard that describes the way information is transferred from the Web to the screen of a mobile device. The protocol was initially developed by four companies: Ericsson, Motorola, Nokia and Unwired Planet. In 1997, these companies founded the WAP Forum, which now includes most of the world's major telecommunications companies. In May 1998, the first edition of WAP was published - v.1.0. However, despite the harmony of the general concept, there were more than enough errors and inaccuracies, and almost a year later, in June 1999, the second version, WAP v.1.1, was presented to the public. In the summer of 2000, the WAP v.1.2 version and its subtype WAP v.1.2.1 were made public. The latest version of WAP v.2.0 at the time of writing appeared in January 2002.

The WAP protocol allows you to download and view special WAP sites on the screen of your mobile device. Before the advent of WAP v.2.0, sites for mobile devices were created in the WML markup language, which provided a rather meager set of tools for page layout. After the release of WAP 2.0, phones began to “understand” sites created in the XHTML MP markup language - a slightly modified version of XHTML. The use of special markup languages ​​instead of HTML, which is used to create regular websites, is due to a number of reasons. Let's look at the most important of them.

At the time of the advent of WAP technology, the main method of data transmission in GSM networks was the CSD protocol, providing a speed of 9.6 Kbps. Loading a regular website at this speed will take a few minutes. Given the high cost of using the CSD protocol, loading even one page would be not only tedious, but also quite expensive.

Working with HTML pages requires relatively powerful processors and large amounts of memory. While modern mobile devices can provide the required level of performance, devices from four to five years ago cannot do this.

HTML pages are designed to be displayed on large desktop or laptop monitor screens with a resolution of about 1024 X 768 pixels. It goes without saying that it is impossible to fit such a page even on fairly “large” mobile phone screens with a resolution of 208 X 176 pixels and less than two inches in size. What then can we say about models with a monochrome screen, which are found now and were quite common a couple of years ago?

For these reasons, an analogue of the HTML markup language was developed that does not have the above disadvantages - WML (Wireless Markup Language), a markup language for wireless devices on the Internet, based on the XML language. The WML language was created specifically for displaying information on a small screen, taking into account the narrow bandwidth of the communication channel, small amount of memory, etc.

The structural unit of a regular website is an HTML document. By clicking on the link of the page loaded in the browser, you load the next page, etc. The structural unit of a WAP site is a WML document, also called a WML deck (Fig. 9.1).

Rice. 9.1. WAP site page.

A WML deck can consist of one or more cards. Each card is limited by tags . Only one map is displayed on the device screen at a time, and the user can switch between them by following links. This WML document structure allows you to significantly reduce the number of requests to the server for information. Listing 9.1 is a simple WML document consisting of two maps.

Listing 9.1. The simplest WML deck

After loading, the first card containing the text will be displayed on the phone screen This is the first card and link This is the link to go to the second map(Fig. 9.2). If you follow the link, only the contents of the second card will be displayed on the screen - text This is the second card.

Rice. 9.2. The simplest WML page.

The widespread use of cell phones with large color screens, as well as the emergence of high-speed data exchange technology in GSM-GPRS networks, led to the emergence of a new standard for creating websites aimed at viewing from mobile devices - XHTML MP.

XHTML (Extensible Hypertext Markup Language) is an extensible hypertext markup language. XHTML is now a standard markup language and is recommended by the W3C to be used instead of HTML. There are several versions of XHTML. To create sites targeted at mobile devices, the XHTML MP (Mobile Profile) version is used. XHTML MP is a lightweight version of XHTML that adds mobile device-specific elements. The structure of an XHTML MP document is very similar to the structure of regular HTML pages. Listing 9.2 is a simple XHTML document that displays the line Hello World.

Listing 9.2. Page created using XHTML M

If you are at least a little familiar with the HTML language, you will notice that the above example is practically no different from a regular HTML document. At the moment, many WAP resources have two versions: WML (see Fig. 9.1) and XHTML (Fig. 9.3). The version of the site downloaded to your phone is selected automatically, or you are asked to choose it yourself.

Rice. 9.3. XHTML version of the WAP site.

Without going into technical details, the operation scheme of WAP services includes three main elements:

WAP browser of a mobile device;

WAP gateway;

server with WML and XHTML content.

Working with the WAP protocol begins with opening a WAP browser, which in turn sends a request containing the URL of a website to your operator's WAP gateway. The WAP gateway converts the WAP protocol request into a request that regular web servers can understand. After this, the contents of the requested page are sent to the WAP gateway. After waiting for the entire page to load, the WAP gateway converts the received data in such a way that it is “understood” by your phone’s browser, and also to provide greater speed of information transfer to the mobile device (for example, to your phone). If you carry out transactions that require confidentiality (financial transactions, transfer of confidential information, etc.), use the WTSL add-on, which ensures encryption of all information sent and received.

The WAP protocol can rely on the operation of CSD or GPRS data transfer protocols. If your cellular operator provides a choice, use WAP-GPRS. It will be faster and cheaper.

To use the WAP protocol, you first need to activate the “Data Transfer” service if you are going to use WAP-CSD, and GPRS-Internet, or GPRS-WAP (different names for the same service) if the phone supports GRPS. After this, you can start setting up WAP.

Most modern cell phone models support automatic configuration to work with the WAP protocol. The mobile operator sends you a special SMS, you save it, after which the phone is ready to work with the protocol. You can initiate sending a message by the operator with WAP settings in two ways:

send an SMS from your phone to a special number;

fill out the form on the operator’s website, indicating your phone number.

You can find out the contents, as well as the number to which the SMS message should be sent, on the website of your mobile operator or by calling the support service. The contents of the SMS will depend on the model of your phone, as well as on which service you are going to use: WAP-GPRS or WAP-CSD. Let us remind you that if you have a choice, choose WAP-GPRS.

After you find out the number and the required content, send an SMS. After some time, you will receive a message confirming the correctness of your order, and then data with your WAP profile settings. Confirm saving the settings. The WAP service setup will be completed.

Some models of modern phones, as well as most older ones, do not support automatic configuration of the WAP service. If your device belongs to one of these categories and you were unable to configure your phone using SMS, you will have to do the setup manually.

As with the GPRS Internet service, you need to create a new data account. Account settings will vary among different cellular providers. You should find them on the operator’s official website or by calling technical support. Do not forget also that for one operator the settings will be different for WAP-GPRS and WAP-CSD. Below, as an example, in table. 9.1 shows the settings for working on the Internet via the WAP protocol using GPRS in the networks of cellular operators Beeline and MTS.

Table 9.1. WAP-GPRS account settings.

In table 9.1 shows the settings for the WAP 2.0 protocol. The settings for WAP 1.x protocols for some operators may differ in the value of the WAP port. For Beeline and MTS operators, this parameter is the same for all protocol versions.

You can choose the profile name and home page at your discretion - the value of these settings does not affect the functionality of the connection. The name is intended to display the profile name in the phone menu. Home page – the page that will load after launching the WAP browser. You can change it, for example to http://wap.mail.ru, if you often use mail. The number of available settings depends on the specific phone model. Data channel (Bearer), access point (APN), user name (Login) And password– settings present in all phone models, since the ability to establish a connection directly depends on them.

If your phone or mobile operator does not support GPRS technology, you need to connect and configure the WAP-CSD service. Settings for WAP-CSD are shown in table. 9.2.

Table 9.2. WAP-CSD account settings

The number of available settings will depend on your cell phone model. Let us remind you that the WAP-CSD connection speed is lower than the WAP-GPRS speed, so choose the WAP-GPRS service if such an option is available.

We are all accustomed to using a mouse (or its equivalent) when browsing websites and cannot imagine how we can do without it. Of course, the creators of the WAP protocol made sure that “travel” on the Web from mobile devices that do not have advanced means of inputting information (mouse, trackball, touch screen, stylus, etc.) would be comfortable. Navigating through WAP pages is carried out in the same way as through the phone menu - using a two- or four-way joystick. Confirm following a link or calling additional functions with two context-sensitive buttons available on all phones.

NOTE

Context-sensitive buttons are buttons whose purpose depends on the task being performed. They are located on the sides of the joystick, immediately below the phone screen. The action these buttons perform corresponds to the name of the “virtual” buttons at the bottom of the phone screen, just above the phone keypad.

To save traffic, and also due to the small screen sizes of mobile devices, WAP sites contain very little graphical information, unlike regular websites. It is also impossible to implement a standard layout of elements on the phone screen: a menu on the left and top of the page, allowing you to quickly move between pages, content in the center.

Basically, the pages of WAP sites are one formatted column of text and hyperlinks, plus one or two banners or logos. The main pages usually consist of only links to other sections of the site; Since their size is small, there is simply no room left for any text.

Pages of WAP sites rarely fit completely on the phone screen. To scroll you need to use a joystick. Since the page content is formatted to fit the width of the screen, you only need to scroll the page vertically. As you can see, everything is simple.

The problem of selecting links has also been elegantly solved. As you scroll through the page one by one, the active link changes. To navigate through it, you need to press one of the context-sensitive buttons responsible for confirming the choice. This is how you move around the site. The active link, as in the case of regular web pages, is highlighted in a different color.

To go to another site, you need to use another context-sensitive button Functions (Options) and in the menu that opens, select the command to enter a new address. A text field will appear in front of you in which you need to enter the site address and then confirm your choice.

Once the page has loaded, you navigate through it in the same way as described above.

In addition to entering the address of the new site, the button Functions (Options) It also allows you to bookmark the current site, quickly jump to bookmarked sites, save pages, go to previous pages, return to the home page, and perform other actions, the meaning of which depends on the phone model.

The variety and quality of WAP resources, of course, is not comparable to the quality and variety of regular websites, which is not surprising - the difference in age of these Internet services is quite large. However, it is quite possible to find out the latest news, weather forecast, check your mail, download pictures, melodies and even play Internet games using the WAP service.

Naturally, well-known sites on the Runet - Yandex, Mail.Ru, Rambler and Aport - have WAP versions. Their address is formed by adding the wap prefix at the beginning.

Website http://wap.yandex.ru can only offer its visitors weather forecasts, TV schedules and exchange rates.

Website http://wap.aport.ru, in addition to weather forecasts and exchange rates, can offer search and WAP mail services, that is, if you have a mailbox on this resource, you can view its contents or write a letter directly from your mobile phone.

On the site http://wap.rambler.ru you can see a standard set of services: TV program guide, exchange rates, weather forecast and WAP mail. There is a poster section that could be very useful, but at the time of writing the book it was not working, but you can view the horoscope, but it is not clear for what period of time. The only worthy service of this site is the ability to translate in four directions: English - Russian, Russian - English, German - Russian, Russian - German.

The site leaves the most pleasant impressions http://wap.mail.ru. The main page has a nice interface. From there, the visitor can immediately go to view their mailbox. In addition to WAP mail, the site provides a search for WAP resources and a fairly extensive catalog of sites. In addition, there is a telephone directory and the ability to download demo versions of games for mobile phones. All pages of the site work and provide the information that is stated in the link.

As you can see, the functionality and richness of the resources considered are generally quite poor. Sites that were originally WAP oriented look completely different. On them you can find paid and free resources for your phones, find out news, weather and find reference information. Since different models have different screen sizes, as well as the format of supported media files, before downloading pictures or ringtones, you will have to select the picture size or download file format. As a rule, the choice is quite large and you can find a file format or picture size that suits your cell phone.

Website http://gidwap.ru contains a catalog of WAP resources, an extensive transport schedule, weather forecast, horoscope and TV program guide. The site has its own WAP chat, divided into categories according to interests, which is constantly attended by a fairly large number of visitors. There is also a fairly thorough reference book containing information on telephone codes, time zones, measures of weight and length, monetary units and barcodes of countries around the world. In addition, here you can find reference information about GPRS and WAP technologies, information about the resources of WAP sites and the possibilities of downloading them.

On the site http://wap.djwap.ru you can find a forum and a large number of both paid and free resources for your phone, including games, music, cool calls, videos, animation, wallpapers and themes. The site has two versions: for viewing from old phones and for viewing from phones that support WAP 2.0. A very interesting opportunity is to obtain background information about the largest cities in Russia. Using a cell phone, driving past some regional center, you can find out the phone numbers and addresses of gas stations, car services, pharmacies, hospitals, hairdressers, bars, exhibitions, museums, etc. The reference information in the Info-Gorod section of the website is really collected so many. On this site you can also always find the latest news from the mobile world.

Website http://fank.ru can offer you just a huge number of simple and animated pictures of various sizes, melodies recorded in various formats, video jokes, clips and commercials. The content is rationally divided into categories, which will prevent you from getting confused in the rather diverse content of the resource. Do you want to meet? Not a problem - in addition to the active chat, the site contains about 20,000 profiles of people looking for new acquaintances. The figure, of course, is not comparable with the number of profiles on well-known dating sites on the Runet (about several million applications). However, if you consider that there are not so many WAP Internet users, the number of profiles inspires respect. The site provides its registered users with an analogue service http://foto.mail.ru– you can upload your photos, as well as view photos of other users. At the time of writing, the site contained about 40,000 photographs. On this resource you will also find weather forecasts, exchange rates, football match results and you will be able to send mail without registering a mailbox.

All of the sites reviewed have links to other resources, and some of them are directories of links. By using them, you can get to many other resources on similar topics that provide entertainment and reference information.

As you may have noticed, almost all of the sites reviewed contain weather forecasts. However, none of them can compete in this area with the resource http://wap.gismeteo.ru– a specialized site whose sole purpose is to inform its visitors about the weather anywhere in the world. Chapter Monthly forecast allows you to clarify the weather forecast for the largest cities in Russia for a month in advance. The conclusion is simple - if you need to know the weather forecast, use the services of this resource.

On the website of the RTS stock exchange http://wap.rts.ru You can find out the RTS indices and the value of shares of the largest Russian companies. The resource, of course, is not as informative as its full-fledged version, but the ability to quickly view it from the phone screen should be of interest to specialists in this field.

News site http://wap.lenta.ru will let you know the latest events. News is not divided into categories, but is presented in a list ordered by date. Using the link Further you will go to older events.

Website http://wap.km.ru more informatively rich than http://wap.lenta.ru. In addition to the latest news, you can find out here the schedule of performances, cinemas, exhibitions, concerts, sporting events, find a job or advertise the sale or purchase of any product.