What's the relationship between TD-SCDMA and Td-lte?

Source: Internet
Author: User

Recently, there are a lot of topics on TD-SCDMA. The point of view is to support and oppose the two factions, and to settle the historical scores. Personally, TD-SCDMA itself is indeed a failure, at least the masses of the eyes are discerning. But also can not completely negate the credit of TD-SCDMA, it is not the key to td-lte development and growth, not to say, but at least for Td-lte laid a foundation.

The negative contribution of TD-SCDMA to Td-lte is that TD-SCDMA and Td-lte do not have a dime relationship. Because both the core technology or network performance is different in nature, so, in addition to the same TDD time duplex mode, the 3G era of TD-SCDMA and 4G era of the Td-lte did not have a lot of contact, Td-lte and TD-SCDMA there is no so-called "evolution" relationship.

If you follow this logic push down, WCDMA and FDD also do not have a dime relationship, they do not have any "evolution" relationship.

As for evolution, let's take a look at how the previous generations were done. GSM evolution to WCDMA, which is recognized by everyone. The second generation of GSM, TDMA is a multiple access way, Gmsk for modulation, duplex mode is based on FDD TDD, the core network of CS domain as the main mobile communication system, and GSM "evolution", the so-called WCDMA, CDMA is a multiple access mode, QPSK for modulation, The duplex mode is FDD, the core network has the CS domain on the basis of the introduction of PS domain.

The evolution of WCDMA to FDD is also universally accepted, but WCDMA and FDD technologies are not more correlated than TD-SCDMA and TDD. In this respect, the issue of evolution does not seem to have much to do with technology.

The so-called smooth evolution means that a system can be smoothly upgraded to another system. Smooth upgrades in communications generally refer to: can coexist with carrier, key technology same, system architecture is the same, and LTE contrast three 3G standard in wireless access network or core network are revolutionary changes, completely lost and 3G of the back-compatible. Embodied in the hardware equipment, often two standard equipment is independent, whether it is BBU, RRU or Acer base station cabinets or antennas are separate.

Of course, now there are also equipment vendors to launch Multimode Bbu and Multimode rru, even antennas can be shared, but this is only "artificially" enforced two or more standard communication protocols to the same device, from logic and protocol, or two incompatible with each other can not smooth evolution of two communication systems, Like many multimode phones now, such as GSM/WCDMA dual-mode, gsm/cdma2000 dual-mode, or even Gsm/wcdma/lte multimode, these are only a number of communication protocols to do a chip, but the nature or the independent of several communication protocol modules together, For example, Qualcomm's Multimode multi-frequency baseband chip.

Today's three 3G formats are not "smooth upgrades" to LTE.

The true sense of smooth upgrades and post compatibility are only: GSM and Grps/edge, WCDMA R99 and fdd-hspa/hspa+, CDMA IS95 and CDMA2000 1X, TD-SCDMA R4 and Td-hspa, LTE and lte-advanced.

Therefore, it is unfair to negate the relationship between TD-SCDMA and Td-lte from the angle of technical difference.

In fact, this is only a continuation of the FDD of WCDMA and TD-SCDMA in the 3G era, between TDD and the more controversial in the 4G era. In the 3G era, TD-SCDMA has been defined in foreign countries as a good complement to WCDMA. Because both are technically characteristic, they can share a core network and the RNC is very similar. Later, TD-SCDMA has not been able to keep up with problems such as the industrial chain and its own technical immaturity.

In other words, from the 3G era, the need for FDD (WCDMA) and TDD (TD-SCDMA) coexistence has begun to be recognized. Without TD-SCDMA to occupy a place in the early morning, Td-lte will not logically be included in the 4G Standard and accepted.

Therefore, TD-SCDMA has indeed laid a certain foundation for Td-lte. As for the contribution of how big, or leave history to evaluate it!

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