Analysis of the future development of digital walkie - talkie and prospects
First, the analysis of digital walkie-talkie With the increase in the number of professional wireless communications users, increasingly tense spectrum resources, market demand tends to diversify, professional wireless communications began to digital development. At present, radio walkie-talkie can be divided into analog communication technology analog walkie talkie and the use of digital technology to design digital walkie-talkie. The former is to modulate the stored signal to the transmission frequency of the intercom, while the latter digitizes the voice from the Mic (Mic) via an analog-to-digital converter (ADC), and the signal is processed and encoded by the built-in DSP (digital signal processor) The signal after that is to be modulated, and the digital-to-analog converter (DAC) simulates the modulated signal and transmits it to the RF transmitter through the antenna. The RF receiver digitizes the analog signal received by the antenna to the digital signal processor's analog-to-digital converter. The DSP software processes the signal - demodulates and decodes, and the digital-to-analog converter simulates it and delivers it to the microphone.
Second, the digital walkie-talkie is the inevitable trend of the future development of walkie-talkie
(A) digital machine technology has obvious advantages
Digital walkie-talkie is a replacement product of analog walkie-talkie, the voice signal in the internal digital processing, and can expand other data applications intercom. It has a completely new technology and is the product of a new era. Compared with the traditional analog walkie-talkie, integrated into the digital FM and other modern communication technology, digital walkie-talkie in the following four aspects have their unparalleled advantages.
1, high spectrum efficiency. Traditional analog walkie-talkie channel bandwidth is 25 kHz, a waste of radio spectrum resources; and digital walkie-talkie bandwidth is relatively narrow, the general channel bandwidth is 12.5 kHz or 6.25 kHz, to some extent, ease the growing shortage of spectrum resources.
2, voice quality improvement. Digital technology is robust against noise, filters out noise and reconstructs signals, offers superior voice quality over analog technology, and increases the effective coverage of wireless communications, making it easy for users to cope with the ever-changing work environment in the field. (figure 2)
3, to provide additional business. Digital interphone with a digital signal processing mechanism inside, you can increase the number of data applications, extensions, such as text messaging, video messaging, telemetry data and other wireless transmission.
4, improve the safety factor. On analog channels, voice signals are easily intercepted. The digital walkie-talkie can be applied to a high level of encryption technology, but also with system authentication, air interface encryption and other security measures, so a higher level of communication security, so as to ensure maximum privacy of user communications.
(B) strong domestic and foreign policy support
At present, the lack of frequency resources has become a professional resistance to the development of wireless communications industry. In order to improve industry development conditions and promote technological upgrading in the industry, some countries have released new frequency planning policies.
China's Ministry of Industry and letter in the 666 document "on the 150MHz / 400MHz frequency band dedicated walkie-talkie planning and the use of related issues related issues" from January 1, 2011 stop approving the new 150MHz and 400MHz (professional walkie-talkies use the band) Analog walkie-talkie models , Do not model the extension of the original analog devices, and in January 1, 2016 to complete the analog products to digital products conversion. The United States Federal Communications Commission (FCC) in the White Paper on Narrowbanding in Professional Wireless Communications states that as of January 1, 2013, professional wireless communication devices that can not operate in the 6.25 kHz communication bandwidth mode or in equivalent mode will no longer be accepted Model approval request, that is, stop analog walkie-talkie model approval. Japan's Ministry of Internal Affairs and Communications in the "on the number of simple wireless import frequency redistribution," the bulletin states that simple radio communications equipment from November 30, 2012 to the narrowband digital transition, and in November 30, 2022 to complete the analog products to Digital product transition.
This shows that "mode rotation" trend of the times.
(C) interphone market prospects
Judging from the international market, the global professional wireless communications market will continue to grow steadily as economic and social development and public safety incidents have drawn worldwide attention and the application of professional wireless communications equipment has become increasingly widespread. The market size in 2009 reached 62.4 billion yuan, is expected to grow to 83 billion yuan by 2013, an annual compound growth rate of 7.4%. Looking at the domestic market, with the launch of China's intercom module revolution, in the transitional period of five years, we must now use the 50 million analog interphone inventory market update, while there are about 500 million incremental market demand each year , From 2011 to 2016 there are 75 million digital walkie-talkies in the market capacity, coupled with the digital walkie-talkie accessories and back-office systems, market prospects are very broad, combined with policy support, digital walkie-talkie will be rapid development, quickly occupy the walkie-talkie market.
To sum up the three major features, making the digital walkie-talkie compared to analog walkie-talkie obvious competitive advantage is the inevitable trend of the future walkie-talkie.
Third, the domestic digital walkie-talkie market analysis of the situation
Recently, I visited several local walkie-talkie dealers and found that the promotion of domestic digital walkie-talkie is still in a slow development stage, mainly in the following two aspects.
(A) sales price is high. It is understood that the United States Motorola XIR series sales price of about 5,000 yuan, Japan's Kenwood NX series is about 4,500 yuan, the sea can reach PD700 price of about 3,300 yuan. The other hand, analog walkie-talkie, the market in the sale of low-end analog walkie-talkie only 400 yuan.
Digital radio sales price is mainly based on the following two points:
1, the cost is higher. The current digital walkie-talkie still uses a general-purpose chip as the core chip, chip features and module settings are not targeted, serious waste of resources. Although the product superior performance, full-featured, but the cost of R & D and production costs huge, so expensive.
2, monopoly serious. Motorola, European Aerospace and other leading wireless communications industry leaders, they dominate the industry standards, patents, core technology has obvious advantages, relying on a strong overall strength and brand image, occupy the global professional wireless communications industry, most of the market Share. The only domestic Haida, North Peak and a few manufacturers to mature mass production of digital walkie-talkie, competitiveness is very limited.
Due to the current average price of digital walkie-talkie is much higher than the price of low-end analog walkie-talkie, the majority of users tend to use analog walkie-talkie, digital walkie-talkie can only be a handful of high-end professional users, which led to the domestic sales of digital walkie-talkie accounted for the entire profession The proportion of wireless communications market is much lower than the global average, the slow progress of the promotion of digital walkie-talkie in China.
(B) the lack of national standards. Walkie-talkie communication, digital walkie-talkie and analog walkie-talkie is different, analog walkie-talkie baseband audio signal, as long as the channel, analog intercom can achieve interoperability. The digital walkie-talkie is completely different, the manufacturers of different digital baseband processing, voice encoding and decoding, 4FSK encoding format and channel interleaving, error correction methods are inconsistent, resulting in different brands of digital walkie-talkie in the same channel can not communicate the phenomenon. In order to solve this problem, DMR / dPMR standards have been established in Europe and related standards have been formed in Japan and the United States. However, there is still no national standard for digital walkie-talkies in China, so some domestic R & D and manufacturing digital walkie-talkies are only developed The standard digital walkie-talkie of the agreement of each enterprise can not communicate with each other, which directly affects the development and promotion of digital walkie-talkie.
Fourth, to speed up the transition of the domestic market walkie-talkie mode
It is foreseeable that the future of digital walkie-talkie is bound to be brilliant, but the current development and promotion of slow. In order to speed up the transition of interphone mode, I put forward two suggestions.
(A) to develop digital standards for the international market
In view of the current development trend of digital walkie-talkie, all Chinese walkie-talkie-related enterprises should actively participate in and promote the development of China's digital walkie-talkie standards, making it a national independent intellectual property rights, and thus effectively promote the development of digital walkie-talkie industry. It should be noted that, as the DMR / dPMR standard in Europe has become the mainstream standard of the international digital walkie-talkie, in order to make our digital products smoothly go to the international market, the standards of the domestic digital walkie-talkie must be compatible with the standards such as DMR / dPMR.
(B) the development of special chips to promote industrial upgrading
Domestic manufacturers to enter the field of digital walkie-talkies relatively late, to compete in the digital walkie-talkie after the system, you must have a breakthrough in radio technology. The author believes that the development of digital radio chip is a good entry point.
If the dedicated chip can be successfully applied, then the cost of digital walkie-talkies production costs and sales prices will drop significantly, directly promote the transition mode conversion, in addition, will form a technological advantage, breaking barriers to foreign barriers to promote the development of domestic enterprises to promote industrial upgrading , Enter the international market, participate in global competition and accelerate the transformation and upgrading of economic development.