The TD-LTE service has been in trial for some time, and it is expected that the commercial operation license will be officially issued at the end of this year and early next year. Many base station operators, terminal equipment manufacturers and chip manufacturers are coveting this pie. The pioneer of commercial operations is China Mobile, but it is estimated that China Unicom and China Telecom are also expected to obtain TD-LTE licenses, and even the licensee has hinted that TD-LTE is a required (common) common standard. It is expected that the deployment of LTE / LTE FDD or other standard telecommunication services is optional (OpTIonal).
Figure: Multi-band support is the main design challenge for LTE chips (Source: Techonlineindia)
Regardless of the base station equipment, end-user-oriented products and chips have encountered a major problem. China Mobile has established a standard that requires terminal chips and products to meet the requirements of 5 modes and 10 frequencies. Paying bills has become a major challenge for chip manufacturers.
The so-called 5-mode refers to LTE / LTE FDD, TD-LTE, TD-SCDMA (including TD-HSPA +), WCDMA (including HSPA +), GSM (including GPRS, EDGE, EDGE EvoluTIon) and other modes, 10 frequency refers to 10 operations Frequency band, the frequency position and channel bandwidth of each frequency band are different.
Qualcomm alone?
The high frequency requirements of 5 modes and 10 modes are a headache for chip vendors, and they believe that China Mobile has issued this rule with a unique Qualcomm. Qualcomm has many 3G technology patents and is the most capable of providing a wide range of chips. The fact also proves There were only two chip vendors that first passed the 5-mode 10-frequency requirements, namely Qualcomm and HiSilicon under the Huawei Group, and then two more, namely Taiwan MediaTek and Marvell.
In order to gain the favor of the big buyer China Mobile, other chip manufacturers have also actively worked hard. For example, Leadcore under Datang Group has been able to support 4 modes, only WCDMA has not yet been supported, and most other companies have up to 3 modes. Claim.
Is it possible to add more support modes after reaching 5 modes? The only possible requirement should be to support LTE-A. As for standards such as WiMAX and CDMA2000 (including EV-DO) are not mainstream, they should not become new requirements. Only chip manufacturers that have already invested in WiMAX development, such as Altair, Sequence, GCT Wait, WiMAX will be treated as a model and integrated.
If LTE-A is regarded as an extension of the current LTE / LTE FDD and TD-LTE, there should be no need for more modes, and if it is regarded as another mode, it will be expanded to 6 modes in the future.
The mode is generally extreme, but the frequency band is not. At present, chip manufacturers have proposed higher support capabilities such as 11-band and 13-band. Altair chips even reach 14-band. However, the distance from the above support to all frequency bands is still far. In other words, LTE / LTE FDD has 29 frequency bands, and TD-LTE has 12 frequency bands.
Multi-band support is the challenge
However, 11 of TD-LTE's 12 frequency bands overlap with LTE / LTE FDD, so there are 30 frequency bands that need to be supported, but the development of frequency bands is still continuing (such as Band 43 in the United Kingdom and Switzerland). With the emergence of new frequency band standards, extensive frequency band support has become a greater challenge for chipmakers.
There are also factors that will require multi-band support. Since there is no globally consistent frequency band, multi-band support is required. It is not like Wi-Fi and Bluetooth all choose the 2.4GHz band.
This also reflects another problem. Recently, 4G spectrum resources are being sold in Taiwan. The United States predated a new sale before Taiwan. Among the new sale, the low frequency 700MHz is the most popular, but it is not the most popular in Taiwan. There are many reasons. The use of new frequency bands to set up base stations requires re-testing and verification, so that current telecommunications providers prefer to purchase existing frequency bands. Only new telecommunications providers will prefer the new frequency bands with less construction burden.
The other is that although 700MHz coverage is large, this is very attractive to the United States and Canada, where the land is sparsely populated, but Taiwan, which is narrow and densely populated, is less attractive. In addition, there were few chips and devices supporting 700MHz in the past, with less procurement options and higher costs. These three points are the reasons why the 700MHz frequency band has not become the hottest bidder.
Returning to the foregoing, how to prevent the chips that support a few unique frequency bands from having higher costs is to allow a single chip to support various frequency bands as widely as possible, and to lower costs in a way that shares the same amount and price. Therefore, 5 modes and 10 bands are not the ultimate requirements. Although the mode may be required again, it is believed to be limited. The larger space for competition and improvement lies in the frequency band.
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