Information document to CEPT PT1 on the possible impacts of SDL adoption in the MHz band

Transcription

1 Jan. 15th, 2015 Information document to CEPT PT1 on the possible impacts of SDL adoption in the MHz band To: CEPT ECC PT1 (Chairman Didier Chauveau) CC: Chairman, ETSI MSG TFES ( Holger Butscheidt, Chairman, ETSI ERM ( Contact: Name: GTI Secretariat Tel. Number: (+86) Address: Attachments: none Dear Chairman of CEPT ECC PT1, GTI (Global TD-LTE Initiative) is an open platform established in 2011, advocating cooperation among global operators and vendors to energize the creation of a world-class and a growth-focused business environment for LTE TDD. GTI aims to build a robust ecosystem of converged LTE TDD/FDD, and speed up its commercialization. With 3 years development, GTI has become one of the most important cooperation platforms with 116 operator members and 97 vendors. The GTI has noted on the 2.6GHz SDL discussion [1] since last ECC PT1 meeting in September GTI would like to convey the views from LTE TDD industry on this issue to ECC PT1 s discussion on this issue. With increased recognition of its value, TDD has gained wide ecosystem acceptance and back from leading operators, infrastructure and device vendors. Unified global TDD allocation in 2.6GHz will enlarge the global market scale for standardized products and

2 facilitate the global roaming. GTI 1 strongly advocate CEPT for your kind consideration to encourage global harmonization of LTE ecosystem and consider the impact while SDL is introduced to 2.6GHz band. Global market updates on the MHz TDD band Due largely to the launch of commercial LTE services in China, but also to a lesser degree in Japan, the United State, Saudi Arabia, and so on, it has boosted the addressable market share for 2.6GHz TDD (Band 41/38). Band 38 has overlapping frequency ( MHz) as Band 41( MHz), meaning that LTE TDD has formed the basis of global roaming in 2.6GHz band. Band 41( MHz) were allocated to China Mobile, China Telecom and China Unicom used for TD-LTE in December, 2013 in China. The decision by operators in China to deploy LTE TDD ensures that a large-scale market and robust ecosystem will be established in 2.6GHz, benefitting all the other TDD markets. China Mobile commercially launched LTE TDD on December 18, 2013 in Band 39, 40 and 41. Over 650,000 base stations were activated by the end of 2014, serving more than 71 million users. China Telecom commercially launched LTE TDD service in Band 41 on February 14, 2014, initially offering service in almost 100 cities. China Unicom commercially launched LTE TDD services in Band 40 and Band 41 on March 18, 2014 in 25 cities and plans to cover 100 cities in SoftBank commercially launched LTE TDD (AXGP) in Band 41 in Feb, The AXGP subscribers have approximated 5,200,000 by the end of September, Following its buyout of Clearwire who owns all 2.6GHz TDD spectrum in US, Sprint stopped selling WiMAX service after 2012 and commercially launched LTE TDD in Band 41. Etisalat (Mobily) commercially launched LTE TDD on September 14, 2011 via its Bayanat subsidiary in band 38 (2.6 GHz). In January 2013, Mobily announced that it had about 1 million subscribers on its LTE TDD network, illustrating the success of its shift from WiMAX to LTE TDD. Summary of launched LTE TDD networks in 2.6GHz band Country Operator Frequency Band Brazil On Telecomunicacoes 2.6GHz TDD Band 38 1 This contribution was approved by majority in GTI Steering Committee. Several operators may hold and express different views among 116 GTI operator members.

3 Brazil Sky Brasil Services 2.6GHz TDD Band 38 Canada Sasktel 2.6GHz TDD Band 41 China China Mobile 2.6GHz TDD Band 41 China China Telecom 2.6GHz TDD Band 41 China China Unicom 2.6GHz TDD Band 41 Japan Softbank XGP/LTE TDD 2.6GHz TDD Band 41 Madagascar Blueline 2.6GHz TDD Band 41 Poland Aero2 2.6GHz TDD Band 38 Russia MTS/Moscow 2.6GHz TDD Band 38 Russia Vainakh Telecom 2.6GHz TDD Band 38 Saudi Arabia Mobility 2.6GHz TDD Band 38 Spain COTA/Murcia4G 2.6GHz TDD Band 38 Sri Lanka SLT 2.6GHz TDD Band 38 Sweden Hi3G 2.6GHz TDD Band 38 USA Sprint 2.6GHz TDD Band 41 LTE TDD networks in deployment or firmly planned Country Operator Frequency Band Bangladesh Banglalion 2.6GHz TDD band 38 Bangladesh Ollo/BIEL 2.6GHz TDD band 38 Belgium BUCD 2.6GHz TDD band 38 Cameroon YouMee 2.6GHz TDD band 41 Denmark 3 Denmark 2.6GHz TDD band 38 Dominican Rep Win Telecom 2.6GHz TDD band 38 Finland Datame 2.6GHz TDD band 38 Ghana Blu Telecoms 2.6GHz TDD band 38 Puerto Rico Aeronet 2.6GHz TDD band 41 Romania 2K Telecom 2.6GHz TDD band 38 UK NSV(BT) 2.6GHz TDD band 38 USA ntelos/dish 2.6GHz TDD band 41 The ecosystems for TDD bands 38 and 41 (2.6GHz) dominate the LTE TDD devices and are almost identical, supported in almost half of all the TDD devices. Availability of devices that can support TD-LTE remains growing. According to GSA statistics, there are 422 devices supporting 2.6GHz TDD in the market in mid-oct Implications in case of SDL introduction in the MHz band We would like to take this opportunity to summarize our views. A. SDL would cause inter-operator coexistence issues in the MHz band which may lead to less efficient use of the band.

4 Operators are well aware of the interference issues in case of unsynchronized TDD networks in the same band; inter-operator coordination, such as choosing a common UL/DL ratio, is recognized as the way forward in order to avoid loss of spectrum in guard bands or operator-specific filters (that may not be easily added to already deployed equipment). SDL/TDD coexistence is a special case of unsynchronized TDD with the additional constraint for which DL-to-UL interference is not mutual (assuming that enb-enb is dominant and UE-UE interference is negligible). Considering that not all operators have the spectrum assets to allow carrier aggregation with other bands, and considering that some TDD networks have already been rolled out in some markets, the introduction of SDL would lead to the need of inter-operator guard bands in some markets. B. SDL non-standalone operation, would split the terminals ecosystem and create negative consequences on UEs roaming and market competition. The existing TDD standalone operation can ensure the accessibility of non-ca capable UEs, especially important for operators with less spectrum assets available. C. SDL introduction would split the B38 UEs eco-system SDL introduction would trigger different UE designs in the MHz band, two different types of UEs in the same band which would weaken the ecosystem and determine negative impacts in terms of roaming. Different CA band combinations for different operators using SDL will further fragment the UE ecosystem. The introduction of the SDL at this time would not allow Europe to take benefits of the established ecosystem of LTE TDD for the MHz band. Introducing a non-standalone SDL carrier in B38 would suffer from: - Throughput loss in case of legacy (i.e. non CA capable) UEs - Limitation in the applicable deployment scenarios - PUCCH congestion on the Macro cell - Limitations to the end user devices roaming ability. On the other hand, TDD standalone B38 operation ensures: - The backward compatibility for legacy UEs - That the band can be used either as Primary Cell or Secondary Cell thanks to the UL channel availability, the UE has the flexibility to access any band with better coverage also ensuring energy saving on the UE side.

5 D. SDL may create negative consequences on market competition While a key target of the regulators spectrum policies is to support the development of an open and fair market environment, both at domestic and global levels, the SDL non-standalone use of the band MHz would not be available to new comers. Overall Remarks and Recommendation With increased recognition of its value, LTE TDD has gained wide ecosystem acceptance and backing from leading operators, infrastructure and device vendors. The consistent global TDD assignment in the 2.6GHz bands will enlarge the global market scale for standardized products and facilitate global roaming. With reference to the downlink-only SDL, the unquestioned benefits deriving from the availability of extra downlink resources could be very well achieved with other UL:DL TDD frame ratios, as already supported in the 3GPP standard. What s more, converged FDD + TDD network which have 18 commercial networks can also achieve above mentioned benefit. Additionally, some commercial FDD operators e.g. in Japan, Singapore and South Korea are deploying or planning converged FDD-TDD networks. In the context of the ongoing discussions, the GTI encourage CEPT PT-1 to carefully consider the possible negative implications in terms of spectrum efficiency, roaming ability, end user ecosystem development and competition dynamics while evaluating the possibility to modify the existing regulatory framework for the MHz band with the introduction of the SDL mode. Industry greatly benefits from stable regulations for harmonized bands, this is especially applies at this time to the 3GPP Band 38 whose LTE-TDD ecosystem has already reached a remarkable degree of consistency. GTI therefore strongly recommends ECC PT1 to take into account the points highlighted in this LS and to keep Band 38 as a global TDD band. References: [1]. ECC PT1(14)113, Orange_2.6 GHz band Least Restrictive Technical Conditions for inclusion in the revised ECC Dec(05)05. [2]. GTI TDD Spectrum White Paper, [3]. GSA Evolution to LTE report, Jan.07th, 2015.