What is 0TA game?

OTA is a technology that remotely manages SIM card data and applications through the air interface of the mobile communication network (GSM or CDMA). The air interface can use SMS, WAP, GPRS, CDMA1X and other technologies. The OTA over-the-air download technology based on short messages came into being based on the premise that users are accustomed to receiving data services through short messages, and has become the simplest and most reliable method in OTA technology. OTA technology based on short messages is currently the most practical solution with the least investment in 2G. It meets users' requirements for business simplicity, ease of use, and downloadability, and has become a powerful promoter of mobile data services. At present, OTA over-the-air download technology based on short messages is mainly targeted at SMS-based information on demand, online SMS games, mobile chat, personal assistants and other applications. Applications such as song downloads and online videos will become easier to use as OTA over-the-air download technology based on short messages is combined with MMS, WAP, GPRS and future 3G technologies.

1. Function and structure of short message-based OTA over-the-air download technology

Short message-based OTA over-the-air download technology means that users can add or delete themselves at any time according to their own needs. The mobile Montnets SMS service menu on the OTA card enables the personalization of Montnets services and real-time business updates, and at the same time enables operators to comprehensively launch various data services more conveniently and quickly.

The OTA menu download based on short messages is realized with the help of STK function and short message channel. The OTA card that supports over-the-air download provides a human-machine interface for users to initiate download applications. The OTA application download server based on user requests, The corresponding service download content is sent to the user's mobile phone in the form of data short message (SIM_Data Download mode), and the download data is transparently transferred to the user's OTA card. The OTA card organizes and stores the download content and implements the corresponding STK card menu. manage.

In addition, operators can use the OTA system to complete the automatic configuration of configuration parameters for GPRS, WAP, MMS, WLAN and other services. The OTA application server packages the parameters in a specific format, and then Form a specific short message and send it to the terminal. If the user's terminal supports the OTA specification, the mobile phone will convert this special short message into the corresponding parameters after the user confirms. Therefore, the OTA system not only brings convenience to the user, but also provides operators with faster way.

2. The impact of short message-based OTA over-the-air download technology on user data traffic volume

2.1 The impact of short message-based OTA over-the-air download technology on user short message volume

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The OTA over-the-air download technology based on short messages will increase the usage of short messages by mobile users. For example, in 2002, Shandong Mobile launched the 32kOTA card based on short message OTA over-the-air download technology, which greatly promoted the popularity of "Monternet" in Shandong. By August 2002, there were 1.5 million OTA-STK card users in Shandong Province, accounting for 20-25% of the total number of users. At the same time, Montnets SMS traffic increased by 25%.

The impact of OTA technology on text messages is reflected in the following aspects:

·The amount of text message data generated by the OTA menu over-the-air download itself

Since the OTA menu is basically It is a service based on SMS, and its data is generally less than 1KB. It is packaged and downloaded through SMS, usually less than one SMS group (10 SMS), and the OTA menu download service only needs to be downloaded once, and does not need to be downloaded and used repeatedly. Therefore, the amount of SMS data generated by the OTA menu over-the-air download itself is small.

·Point-to-point SMS business

The main impact on mobile-to-mobile short message services lies in instant messaging services such as Mobile QQ. Due to the widespread use of instant messaging services on the Internet, mobile The OTA menuization of the instant messaging service will simplify the use of this service and promote the usage of this service.

In addition, because users can send greeting cards or greetings to each other's mobile phones online through the OTA menu, this will increase the volume of short message messages between users, allowing popular electronic greeting cards on the Internet to be transplanted to mobile phones, increasing the use of SMS services. Volume

·On-demand SMS services

Since existing on-demand services such as mobile banking and mobile securities will be integrated into the OTA menu, using these services will become easier and mobile users do not need to remember With the service code, you can select application services in the menu of your mobile phone. At the same time, users can choose their favorite business to customize the menu. This has greatly stimulated the usage of on-demand services.

·PUSH service

OTA provides operators with a simple and convenient means to proactively send messages to users. PUSH business can realize the launch of new services, the sending of advertisements, etc. With OTA technology, PUSH business will be convenient to use.

Since the short message service does not have high requirements on terminals and user levels, the short message service is undoubtedly the most universal mobile data service for mobile users. Therefore, due to the launch of OTA, users' BHSM value and SMS service usage will be greatly increased.

2.2 OTA over-the-air download technology based on short messages causes changes in users’ usage of other data services

Because the OTA menu functions as a mobile Internet portal, in addition to being related to SP The increase in the volume of short messages can also trigger users to use GPRS and other technologies to download other applications (such as songs and pictures). First of all, by using the OTA system to complete the automatic configuration of configuration parameters of GPRS, WAP, MMS, WLAN and other services, it can facilitate users to use these services and reduce the complexity of using these services. In addition, users can be guided to use these services through the OTA menu. Therefore, OTA over-the-air download technology based on short messages will increase the usage of other data services by users.

3. The impact of short message-based OTA over-the-air download technology on the core network

3.1 Equipment that needs to be added to the network

Operators must provide short message-based OTA over-the-air download technology OTA over-the-air download technology requires the addition of an OTA application download server. A separate platform approach is adopted to connect the OTA application download server to the internal LAN of each provincial and municipal company. Each provincial and municipal company determines the number of servers based on the number of users in the province and the processing capabilities of the SMS gateway. , hardware configuration and specific connection points.

The main indicators corresponding to the OTA application download server include throughput, storage capacity, and SMS gateway compatibility. The configuration parameters include ICP access number, ICP password, enterprise code, enterprise password, access port number, SMS gateway public network IP, SMS grouping value, OTA download key, and remote file update key.

The main requirements are as follows:

——The OTA system platform must be used for transmission and interaction with existing gateways in each province. If necessary, it should be supported at the same time;

——In the simulated test environment, the OTA system platform has a processing capacity of no less than 20 MO/s when a single M0 returns a single MT. The system's platform can store MO/MT log data for 6 months under the condition of 5 million users;

——Online customized server: It can be set up together with the OTA application download server, or set up separately.

3.2 Devices affected by the network

SMS gateway: It needs to be connected to the OTA application download server and add the ICP access number of the OTA application download server. The processing capacity of the SMS gateway needs to take into account the MO and MT requests of the OTA application download server, as well as the increase in user BHSM caused by the OTA menu. Taking into account redundancy, the busy hour processing capacity of the SMS gateway should be improved accordingly.

SMS center: The processing capacity of the SMS center needs to take into account the MO and MT requests from the OTA application download server, as well as the increase in user BHSM caused by the OTA menu. Forecast the business volume of MO and MT modes respectively, consider the redundancy of 15% for the equipment processing capacity, and calculate the business demand and equipment demand.

The number of No. 7 signaling links required by the SMS center is adjusted according to the processing capacity requirements of the SMSC during busy hours.

4. The impact of short message-based OTA over-the-air download technology on wireless networks

From the perspective of wireless networks, the introduction of short message-based OTA over-the-air download technology mainly causes users Increase in SMS usage. On the current GSM network, most SMS short messages are still carried by the control channel (SDCCH), so the configuration of the SDCCH needs to be increased accordingly.

We take the download time of the MO service with the minimum data bytes as an example for analysis. The command data of the M0 download request is: 1 byte of command type, 1 byte of command length, 3 bytes of MO service index in the command parameters and 2 bytes of available space of the card, ***7 words section, plus 23 bytes of secure application data***30 bytes. Therefore, the data unit length of the CM sublayer of the M0 download request is 141 bytes. We know that there are two multiframe structures in the GSM network, one is a multiframe composed of 26 TDMA frames, used for business channels, such as TCH SACCH business channel: the other is a multiframe composed of 51 TDMA frames, used for Control channels, such as the Standalone Dedicated Control Channel (SDCCH) for transmitting short messages. At the physical layer, a TDMA frame lasts 4.615ms. Because the control channels (BCCH, CCCH, SDCCH SACCH) are arranged in a multiframe composed of 51 TDMA frames, the time required to send a 141-byte MO download request short message on SDCCH is t=[141/23]* 51*4.615ms=1.65 seconds.

Downloading a service may require up to a dozen text messages. Assume that the gateway group value is 10 and the number of service text messages is 20. The channel occupancy time of MO download for this service = MO download application time 20 × each The download time of a business text message and the confirmation time = 56 seconds. Less than 16merl. And users only need to download a certain business once. Therefore, the downloading of 0TA service application data itself has little impact on the SDCCH configuration of the wireless network.

Due to the use of 0TA services, users’ SMS usage for specific services will increase significantly. When specific services are used, the wireless channel occupation time of business text messages is generally the uplink transmission time and the downlink occupation time is about 5 seconds. Although the wireless channel occupation time of the service is small, due to the large usage, it will have a certain impact on the configuration of SDCCH.

Therefore, the specific SDCCH configuration can be based on the increase in short message volume caused by the introduction of OTA, adjust the SDCCH call model, and calculate the traffic volume that needs to be allocated to the SDCCH channel. According to the traffic volume that needs to be allocated to the SDCCH channel, check the Irish table to know the number of logical channels of the SDCCH that should be allocated.

0TA business can not only increase the volume of SP-related short messages, but also trigger users to use GPRS and other technologies to download other applications (such as songs and pictures). Therefore, it will also affect the configuration of the GPRS wireless channel.

5. The development direction of 0TA over-the-air download technology based on short messages

5.1 The development of 0TA bearer mode

Because 0TA is based on short messages. Therefore, its development should follow the development of short messages. Disadvantages of SMS: The message format is simple, only supports simple text, and cannot transmit images or audio information. At the same time, SMS message length is limited. If the business application data sent is too long, it needs to be split into multiple short messages. The result of segmentation will make SMS more expensive than other data carrying methods. Due to these two shortcomings, the current OTA menu is simple. When downloading large services, it needs to be processed in groups and strips, which results in long and discontinuous downloading of large services and increases the possibility of unsuccessful service downloads.

In addition, the SMS protocol data unit (PDU) defined in GSM03.40 fixes various header fields, which is not efficient and greatly reduces the adaptability of SMS.

Compared with GPRS and USSD, SMS provides low data transmission rates and long waiting times, mainly because SMS uses a very slow signaling channel.

The main difference between SMS over GPRS and the original SMS is that the original SMS passes the MM (Mobility Management) sublayer on the wireless port, using SACCH (Random Access Channel) or SDCCH (Dedicated Control Channel) For transmission, SMS over GPRS uses PDTCH (Packet Traffic Channel) for sending and receiving. The original SMS is carried through SCCP on the A interface, while SMS over GPRS is carried on the Gb port, which reduces the need for SCCP links, lowers the cost of data downloading, and increases the speed of OTA menu downloading.

5.2 Development of business model

Due to the limitations of GSMll.14, the interface between the SIM card and the mobile phone currently only supports limited functions, such as making calls and sending text messages. Support for new services and features is limited. In addition, various mobile phone manufacturers have different levels of support for GSMll.14, and generally only simple functions of GSMll.14 can be used. It is foreseeable that in the future, on the basis of supporting SMS services, the 0TA menu will use a business mechanism similar to MMS and expand to stimulate the network side to generate other data services by sending SMS messages. See Table 1 for specific business models.