“The big push towards the Cloud, the Internet and ARM devices where contents of all kinds will drive sales where even TV and media will also embrace as more seek to drive costs down with an explosion of data to target customers where traditional media cannot provide, innovations will drive changes as global companies fill in the gaps to drive consumer demand with greater ROI.” – Contributed by Oogle.
TD-SCDMA (UTRA-TDD 1.28 Mcps low chip rate)
TD-SCDMA uses the TDMA channel access method combined with an adaptive synchronous CDMA component on 1.6 MHz slices of spectrum, allowing deployment in even tighter frequency bands than TD-CDMA. However, the main incentive for development of this Chinese-developed standard was avoiding or reducing the license fees that have to be paid to non-Chinese patent owners. Unlike the other air interfaces, TD-SCDMA was not part of UMTS from the beginning but has been added in Release 4 of the specification.
Like TD-CDMA, it is known as IMT CDMA TDD within IMT-2000.
New TD-SCDMA with automatic switching to Extended WiFi
Time Division Synchronous Code Division Multiple Access (TD-SCDMA) or UTRA/UMTS-TDD 1.28 Mcps Low Chip Rate (LCR), is an air interface found in UMTS mobile telecommunications networks in China as an alternative to W-CDMA. Together with TD-CDMA, it is also known as UMTS-TDD or IMT 2000 Time-Division (IMT-TD).
The term “TD-SCDMA” is misleading. While it suggests covering only a channel access method based on CDMA, it is actually the common name for the whole air interface specification.
TD-SCDMA uses the S-CDMA channel access method across multiple time slots.
TD-SCDMA was developed in the People’s Republic of China by the Chinese Academy of Telecommunications Technology (CATT), Datang Telecom, and Siemens AG in an attempt to avoid dependence on Western technology. This is likely primarily for practical reasons, since other 3G formats require the payment of patent fees to a large number of Western patent holders.
TD-SCDMA proponents also claim it is better suited for densely populated areas. Further, it is supposed to cover all usage scenarios, whereas W-CDMA is optimised for symmetric traffic and macro cells, while TD-CDMA is best used in low mobility scenarios within micro or pico cells.
TD-SCDMA is based on spread spectrum technology which makes it unlikely that it will be able to completely escape the payment of license fees to western patent holders. The launch of a national TD-SCDMA network was initially projected by 2005 but only reached large scale commercial trials with 60,000 users across eight cities in 2008.
On January 7, 2009, China granted a TD-SCDMA 3G licence to China Mobile.
On September 21, 2009, China Mobile officially announced that it had 1,327,000 TD-SCDMA subscribers as of the end of August, 2009.
While TD is primarily a China-only system, it may well be exported to developing countries. It is not likely to be replaced with a newer TD-LTE system over the next 5 years. The present TD-SCDMA can be furthur developed to fully utilised the spectrum by studying the way ZFS technology packs data for transmission to create a new alogorithm. TD-LTE network is too expensive, it is not compatible to new future standards where you not only have to change base stations but handsets as well.
More than 660,000 commuters are now accessing Virgin Media’s wireless network from ticket halls to platform level on the London Underground, the telco claimed today.
It said it was extending free access to the service, which doesn’t reach into tunnels and requires users to register with an email address, until the end of 2012.
The company had originally planned to begin charging non-Virgin Media customers for its service with the exception of a limited offering “including TfL’s journey planner and entertainment and news content useful for a commute to work or trip into town”, which was expected to continue to be free.
Now the entire service remains gratis until the start of 2013, the company has announced.
Virgin Media also appears to be moving more slowly than planned in terms of its deployment of its Wi-Fi network underground. In June this year the ISP said it would hook up 82 stations on the tube network by the end of July with its service.
However, it confirmed today that it had fallen short on its rollout. Virgin Media said that 72 London Underground stations had so far been “brought online”. This time it was also shy about how many more would get the service before the end of 2012.
It had previously said that a further 38 stations had been earmarked to begin offering internet access by the end of the year.
Here’s a canned statement from Virgin Media boss Jon James about keeping the service free for a little longer:
Wi-Fi on London Underground has been an incredible success with hundreds of thousands of people kept up-to-date and entertained whilst travelling around our capital city. Commuters and visitors will be able to make use of the internet throughout 2012 and we’re in positive talks with potential wholesale partners to ensure a fantastic experience for all Tube passengers throughout 2012 and beyond.
TD-LTE offers asymmetric use of unpaired spectrum.[jargon] It allocates separate channels for outgoing and incoming signals, emulating full-duplex transmission over a half-duplex communication link.The frequency bands used by TD-LTE are 3.4–3.6GHz in Australia and UK, 2.57−2.62GHz in the US and China, 2.545-2.575GHz in Japan,  and 2.3–2.4GHz in India and Australia. The technology supports scalable channel bandwidth, between 1.4 and 20MHz. A typical range is up to 200 metres (660 ft) indoors on a 2.57–2.62GHz radio frequency link.
TD-SCDMA uses TDD, in contrast to the FDD scheme used by W-CDMA. By dynamically adjusting the number of timeslots used for downlink and uplink, the system can more easily accommodate asymmetric traffic with different data rate requirements on downlink and uplink than FDD schemes. Since it does not require paired spectrum for downlink and uplink, spectrum allocation flexibility is also increased. Using the same carrier frequency for uplink and downlink also means that the channel condition is the same on both directions, and the base station can deduce the downlink channel information from uplink channel estimates, which is helpful to the application of beamforming techniques.
TD-SCDMA also uses TDMA in addition to the CDMA used in WCDMA. This reduces the number of users in each timeslot, which reduces the implementation complexity of multiuser detection and beamforming schemes, but the non-continuous transmission also reduces coverage (because of the higher peak power needed), mobility (because of lower power control frequency) and complicates radio resource management algorithms.
The “S” in TD-SCDMA stands for “synchronous”, which means that uplink signals are synchronized at the base station receiver, achieved by continuous timing adjustments. This reduces the interference between users of the same timeslot using different codes by improving the orthogonality between the codes, therefore increasing system capacity, at the cost of some hardware complexity in achieving uplink synchronization.
If you compare the difference, you will notice the limitations, I have invented a new standard, using basic TD-SCDMA technology and Extended WiFi, where if you want with present technology, to manually switch networks on your smartphone, but I am not satisfied with the present, new technologies will automatically switch networks between the two, I have studied the specs and both can support the Internet highest bandwidth, to create the next standard where it is possible to encrypt all communications, at the lowest cost possible to rival today’s GSM networks which is not efficient and not possible to support even higher bandwith than LTE networks. This new standard support routing voice and video communications over the Internet. If I want I can easily modify China network to support the new standard, by studying the data paths to improve the efficiency, modifying the protocol to support even higher data paths using Time based compression standards where it is possible to fill in lapses to squeeze even higher data transmission by filling in the blanks. There may temporary technical glitches with the present Internet, the next generation Internet will support 100 billion devices with no issue.
– Contributed by Oogle.