Wither invite! The smartphone inserts two pieces of telegraphic card to go up from the technology at the same time can come true, inscribe for instance advocate the says old man-machine previously can insert two telegraphic card really. But the smartphone of great majority can insert a piece of telegraphic card only now, insert the 2nd piece to cannot identify again. Because,this basically is the following:
One, open patent fee high
The patent of telegraphic CDMA technology is to master in " base band mad demon " in understanding a hand high, include the CDMA EVDO of the CDMA 1x of 2G and 3G. Although telegraphic 4G is not CDMA, want to call, hair short message, still must use CDMA network.
And connect high besides manufacturing SoC chip, origin of another big main gain is base band collect fees. Every sell mobile phone manufacturer a mobile phone of a telecommunication, be about to pay to connect brushstroke patent fee high to use. Because this cost calculates according to base band, so if be double telegraphic base band, be about to know the patent cost of double high, raised the manufacturing cost of the mobile phone greatly.
Opposite shift and the 2G GSM patent that UniCom uses are not connected high, mobile 3G TD-SCDMA and 4G TD-LTE are China of mobile and own research and development. Although TD-LTE technology also involves one part to connect patent high, but after passing alternate accredit, charge wants than CDMA patent a lot of lower. Although final FDD-LTE is to connect hold patent high, but connect high compete for the TD-LTE technology with China, reduced the patent cost of FDD-LTE actively. It is OK that so present entire network connects a mobile phone implementation moves or when couplet collude double card, because CDMA patent is too expensive,have telecommunication only, and cannot at the same time double card.
The machine of a few old people in the past, mountain fastness machine, itself won't pay to know any cost high, also be indifferent to so use a few telegraphic base band. Existing minority is additionally normal after the mobile phone passes broken solution, double card also can use telecommunication double card, but this kind of circumstance is very scarce.
2, double telegraphic demand is not big
Cost of mobile phone of double telegraphic card is higher, and user of card of telegraphic mobile phone is original not much, those who have demand of double telegraphic card is fewer. If mobile phone manufacturer is special produce double telecommunication to block a mobile phone in the light of user of this one fraction, may final sales volume has tens of thousands of only just, will tell from the angle of profit is apparently not of be to one's profit.
Do not cross this two years as all sorts of fictitious operation business arisen, what the discharge of very much cheap be to one's profit gets stuck is telegraphic network, the requirement that uses two pieces of telegraphic card at the same time so also is increasing slowly. Be replaced by LTE network gradually as telegraphic CDMA network on the other hand, telegraphic mobile phone need not pay so exorbitant patent fee again, future appears the possibility of mobile phone of normal telecommunication double card is very large also!
