CTM and personal communications services

This paper introduces the concept of ETSI recently proposed by CTM: that is, based on the DECT technology in the PSTN, ISDN based on the integration in technology to achieve personal communications business, and the CTM network structure, analysis of CTM personal communications business market situation, and finally introduced CTM in Europe, the development and application of the status quo.

1 Introduction

In recent years, the rapid development of mobile communication market indicates that mobility is a major development trend of subscriber telecom business, and the market hotspot has shifted from traditional form of mobile communication to personal communication. Wireless technology provides a good choice for the mobility requirements of wired users. In addition, a large increase in wireless users ensures the cost of wireless solutions is reduced. The final realization of personal communication will not be based on single technology but on the hybrid technology based on all technologies such as PSTN, ISDN, GSM, CDMA, DCS1800, DECT, PACS and PHS. (Computer science)

CTM (cordless Terminal mobility) is a recent ETSI approach to the development of personal communications services (PCS) based on DECT technology. CTM allows personal cordless terminals to communicate by using a single business registration registration via a compatible base station based on DECT cordless technology, which meets the requirements of PCs to provide high quality communications, single billing, and unique numbers wherever and whenever. Although CTM does not provide terminal mobility for a typical cellular mobile telecommunications network, it can provide Low-cost, high-quality, mobile telecommunications services for a large number of commercial and private users, and is suitable for large users without the need to consume a lot of wireless spectrum (relative to cellular technology). CTM can serve as a complementary business for cellular telecommunications, not as a competitor to the cellular telecommunications business.

2 CTM Personal Communications Business profile

2. 1 Requirements of users and telecommunication operations departments

User requirements: In general, users are interested in the Low-cost access to quality telecommunications services at all times, preferably with only one billing and single number. Second, users also want to manage their files at any time by using comfortable terminal equipment and friendly interface programs. Another important requirement is that users can safely control their own private files according to their own choices.

Telecom operations requirements: For the Telecommunications Operations department, the key to providing new business is to minimize the necessary investment costs and the additional costs per user. As a result, the existing infrastructure, procedures and norms must be used as much as possible. In addition, there is a key issue to ensure accurate billing and efficient operation and maintenance management, as well as the provision of a confidentiality scheme followed by a wide range of access technologies and open Network Regulations (ONP) of various (transmission and switching) network technologies.

2. 2 Structure of the CTM

CTM based on the DECT technology, in the PSTN, ISDN based on the integration in technology to achieve personal communication. It can be used as a way to achieve personal communications business or personal mobile Telecommunications (PMT) goals. In principle, CTM can support all the businesses supported by the fixed network, in addition, it allows cordless end-users to move between two base stations and roam between two communities; CTM use a mobile phone that can be used in a variety of environments (different environments refer to public, semi public, commercial and residential), Its business quality is as good as wired, providing seamless switching based on access levels and transmission characteristics (sound quality, latency, and echoes).

The key feature of CTM is that users can roam in different areas and across different environments using the same phone. When a user can initiate and receive a call while in the Operation area, a smart device such as voicemail will process the call if the user is not present when the call arrives. When the user returns, the user can receive and recover the call, based on the location of the network record (automatic location update), with voice prompts.

In public, the access element is called a wireless Exchange (RE), which is here the base station controller (without any Exchange capability). The interface ETSI between the base station controller and the public wireless base station does not have a defined standard. In order to reduce the access investment, the re and Le interfaces should be covered with at least 2 of the existing copper wire. 5 km. In the air interface, BS and mobile phones must conform to all mandatory gap regulations in public places to ensure normal operation in different situations; Re and backbone le interfaces have been standardized (i.e. pra+, adding DSS1 signaling on the PRA interface to support the necessary mobile management messages) Mobility management comes from one side of the backbone, that is, increasing the call independent module on the Le side (including automatic location registration, logoff, and terminal authentication), identifying the user location at the business Control Point (SCP) to provide roaming services throughout the Operation area.

In a WPABX, the access element is mixed with the re and the function of the second, which acts as a local user (PRA with Le's interface) and the former as an Access user (pra+ with Le's interface). The CTM access services provided are the same as in public places. This environment is applicable to airports, shopping malls, large business groups, etc.

In a commercial environment, the Local database (HDB) is connected to the WPABX without the need to be enhanced (for PRA) and the WPABX and Le interfaces are required to be WPABX, and the air interface must conform to the gap standard, only within a limited area by providing control of internal user movement without roaming services.

Because of the low penetration rate of ISDN, the current residential situation is actually used in the backbone of the PSTN network (here Le contains in the function), need to complete the user and in the connection between. This uses a/b line to implement the connection between the user and in. The local wireless base station (Hrbs) transparently delivers DTMF voice and is transformed between the required A/B line and Gap protocol in the air interface (while for ISDN, a D channel instead of A/b line is used to complete the connection between the user and in). In most cases, users are not required to intervene because the network maintains a tracking user location when connected to a user's fixed phone line pair.

Backbone online, le is connected to the backbone exchange according to the network topology structure. In Smart Network (in), multiple business exchange points (SSP) can be connected to a business control point (SCP). In large-scale applications, several SCP can exist. The SCP that serves a zone is called the local SCP for that region, and the SCP that stores the user data for a CTM user is called the scplocal of that user (Scphome). If a CTM user roams to a zone, scplocal copies the user data for the CTM user in Scphome. SCP is interconnected through the SS7 signalling network, and business development and management is carried out in the Business Management Network (SMN), providing a preferred target network for CTM functions as a public ISDN network.

At the top of the network to do a lot of work, its main part for the IWU Mobile management, attribution location Database (HDB), Authentication Center (AUC) and CTM Access specification cap. The work is done by software, which is divided into function module, authentication and encryption function module, wireless Mobile terminal registration and cancellation function module, location registration and location Update function module.

2. 3 PCs implemented with CTM

In CTM, the ability of mobility management can be logically divided into the following functions:

Personal Mobility (PM): The network supports the ability of users to move between wireless access and/or wired access, allowing users to receive calls on any terminal based on their personal numbers.

Business Mobility (SM): The network provides the user's personal business information and the ability to identify the user's access location by supporting terminal and/or personal mobility.

Terminal Mobility (TM): terminals and associated networks support the ability of mobile services (for example, switching), and the network maintains a tracking terminal (terminal location registration and deregistration).

2. 4 CTM's Business

CTM offers the following business:

-Telephone services, including fax operations, emergency call operations and data services.

-Multiple-occasion roaming (residential, work, private, and densely populated areas), which can range from the region to the designated region and the country-wide.

To achieve personal mobility by using the Smart User business Card (smart card) of the CTM user and upt user.

. Low-cost mobile calls.

To support the transparent delivery of supplementary services to the whole network.

3 Advantages and market situation of CTM

3. 1 Advantages of CTM

As mentioned earlier, CTM is considered to be the first step in the development of the next generation of mobile communications.

For telecoms operators, investment spending and the full use of existing public infrastructure must be taken into account. CTM represents a full-service business opportunity (even the complementary business is also fully transparent), the technology using advanced, Low-cost cordless technology, can choose to cover a region, the region, the ordinary people most of the time in this life. On the other hand, in order to reduce the threat posed by the competition among the cellular operators and to occupy a greater market share, it is also logical to choose CTM.

For operators who do not have a cellular operating licence, CTM offers them a good opportunity by using the DECT band.

From a purely technical point of view, the use of DECT technology has many advantages: DECT need not frequency planning; Generally speaking, DECT's indoor situation is very good, the DECT business capacity is much larger than the cellular system, but the relative cost is very low, in some business environment even is irreplaceable.

3. 2 CTM The market situation of personal communication business

The rapid development of communication market indicates that mobility is a developing trend of subscriber's telecom business. In addition, the telecommunications business and unique user identity is increasingly demanding, that is, through a single telephone number to achieve access to the network whenever and wherever.

Another important factor in assessing the market is the cost of terminal prices and the access costs of mobile services, and the home and office cordless terminals have proven to be very attractive to end users and have developed rapidly in many countries (currently not yet in our country). Experiments in some countries have shown that the application based cordless terminals have a large potential market. Some users who are interested in mobile communications are struggling to pay for the high cost of cellular mobile communication systems, or are not prepared for this, and CTM can meet the needs of these users.

Development and application Status of 4 CTM in Europe

France: in Saint Maur des Fosses near Paris, the Prophase CTM business has been commercially operational and covers an area of about 2 km2. The area is populated by about 1200 houses and 1100 apartments. 400 base stations have been invested in the area to ensure indoor communications. The base station is connected with the base station controller through the twisted pair, while the base station controller is connected with the mobile control center through the optical fiber.

The construction of the regional network began in 1994. At present, the total population of the area is 6000 people, 600 of whom use CTM business, the object is "home user". The current business is: voice mail, indent dialing, tripartite meetings, dialing by name, and so on. An unanswered call automatically transfers to the voicemail by calling a number for the home. Young people are the main users of the business.

Spain: Similar operations have been operating in Madrid, Spain for several months, unlike France, where the French CTM cover residential areas, while Spain's CTM serves a large business centre, including many restaurants, bars, cinemas and small shops. The main results of the experiment were: compared with the use of fixed-line telephones, the average number of CTM users increased by twice times in some cases.

Italy: In January 1997, the first real CTM business began to be heavily used in Italy, and this year, residents of 30 major cities in Italy enjoyed the business through local mobile and in infrastructure equipment. The business has a very intensive coverage and, in most cases, includes all urban areas. If wireless coverage is not continuous, it is planned to cover densely populated areas of the downtown area, such as train stations, airports and business centers. The business also serves the main tourist attractions.

5 Conclusion

Through the above analysis, we believe that:

The CTM system requires that infrastructure such as ISDN, PSTN and in-grid be perfected, with PSTN or ISDN as backbone, and the CTM system implemented in the network.

CTM based on DECT protocol and universal Access specification gap, the existing DECT various applications (WPABX, home, commercial, WLL, etc.) based on the provision of wireless terminal mobile and other more powerful functions, need to do a lot of work at the top of the network (such as the location of the database, authentication center, etc.), There is also a corresponding CTM access specification (currently DECT system does not have this requirement).

CTM Although there are several experimental systems, but these are only early experimental systems, such as the Alcatel public DECT/CTM system Alcatel 9550, and Le's interface is pra+, air interface is dect/gap.

A mobile terminal in CTM can be used in a variety of environments, such as home, commercial, WPABX and so on, to provide the slow mobile service within the system coverage and to support roaming, finally realize the goal of personal communication business.