A snapshot of LTE 800 in Europe Legal framework and interference cases (public version)
Michel Gascoin, NRK, Norway Updated 29.09.2015
FREQUENCY ISSUES with an impact on DTT •
Launch of LTE services in the 800 MHz band
•
Future clearance of the 700 MHz band
•
UHF band in the long run
We must protect today's viewers from tomorrow's interference
Political arguments for releasing spectrum • Generate revenue for governments • Face an increasing need for mobile broadband • Reduce the digital divide within a country • New source of income for Mobile Network Operators (MNO) Prerequisite: Existing digital TV (DTT) services must be safeguarded
Countries with LTE800 in Europe (as of spring 2015)
Austria Belgium Croatia Czech Republic Denmark Estonia Finland France Germany Greenland Iceland Italy Lithuania Macedonia Moldova Monaco
Netherlands Norway Portugal Romania Russia Slovakia Slovenia Sweden Switzerland United Kingdom
Time for evaluation !
Ireland (Spain) (Poland)
In operation Planned in 2015 No info
Process for the release of the 800 MHz band
Co-primary assignment of 790-862 MHz Co-existence studies, recommendations…
Commission decision 2010/267/EU
National spectrum licensing (LTE)
Survey about national licensing conditions
What legal framework/licensing conditions were chosen by each administration? Are there best practices? Any lessons to learn for future spectrum release?
Is DTT below 790 MHz safe?
10 participating countries
An extensive questionnaire…
1.
What 800 MHz spectrum is currently licensed and used in your country?
2.
What are the protection requirements for LTE-DTT coexistence?
3.
How interference cases are dealt with?
4.
Economical aspects (who pays for what)?
5.
What is the current situation concerning LTE800 interferences?
1. WHAT SPECTRUM IS LICENSED AND USED FOR LTE800?
Use of spectrum: findings • Few license requirements to use all the released spectrum • Some “priority coverage areas” are defined, but are limited in extent and in offered bandwidth • Current deployment mainly in populated areas, densely in cities in some countries Efficient use of spectrum? Real intention to bridge the “digital divide”? LTE800 used for… capacity? Coverage? As a replacement for Wifi?
2. WHAT ARE THE PROTECTION REQUIREMENTS FOR LTE-DTT COEXISTENCE?
Protection requirements: findings • Administrations expressed a clear intention to protect DTT • In practice: • Not all TV installations and households are entitled to protection • MNO are free to roll out without conformity check • Only two countries have systematic procedures for checking the deployed mobile network • MNOs roll out plans are not made public in most cases
MNOs have the sole responsibility to avoid or solve/mitigate interference problems
3. HOW ARE INTERFERENCE CASES DEALT WITH?
Mitigating interference: findings • Mitigation organisations/call centers exist in 7 out of 10 countries • Filters is a preferred means of mitigation • However: • To check if LTE is the cause of interference is difficult for a call centre or the public, even for professionals! • Unclear mechanisms to make sure that adequate filters are actually sent and fitted properly
Who could/would DTT users call when TV reception is bad? How feasible and economically rational is it to check: • •
if LTE is the cause? if a filter actually solved the problem?
4. WHO PAYS FOR MITIGATION?
Economical aspects: findings • MNOs are expected to cover the costs for: • Mitigation org. /call center (6 countries out of 10) • Filters (7 countries out of 10) • Filter installation (4 countries) • New antenna installation (2 countries)
• In 4 countries, it is unclear how costs are covered Could one expect the viewer to find out a solution by himself and install it by himself properly? What if a filter does not solve the problem? What would could a viewer do?
5. WHAT IS THE CURRENT SITUATION CONCERNING LTE800 INTERFERENCES?
Publications… •
No available information in the majority of countries
•
Very few publications and official statements
•
Rumours, rumours, rumours… Reported cases
Period covered
Germany
20 cases (11/2014)
2012
Norway
1332 cases (4/2015)
2014-2015 (1 year)
UK
6710 cases (6/2015)
2013
France
49101 cases (5/2015)
2012
(130587 to 193147 households)
Other countries
No data
The situation in France as in CEPT report SE7(14)110* (oktober 2014)
Mainly overloading and receiver blocking *Information consistent with the announcement from ANFR about 32000 cases (Spectre & innovation, 27th November 2014)
Update in France (May 2015) •
9287 base stations in operation
• 49101 complains received, of which: •
36908 (+70%*) from individual houses •
•
12193 (+56%*) collective houses
Estimated total amount interfered households:
between 130587 and 193147 (14, respectively 21 household per base station)
*compared with last detailed update in October 2014
Interference: findings • Many cases of antenna amplifier overloading • A majority of identified LTE problems are solved with a filter, if fitted properly (before the amplifier) • Still: • Very little information available • Very large discrepancy: Germany vs. France
Few interference cases? Unidentified cases? Hidden figures/deliberate opacity? Or just no feedback from DTT users etc.?
Is DTT below 790 MHz safe?
YES! • Very few reported interference cases • Filters seem to solve most problems
MAYBE NOT… •
FDD 1 not in use on a large scale yet
•
Real technical challenge to assess LTE problems in practice
•
Uncertainty that problems are reported by DTT users
•
Opacity regarding real disturbance
We might face a silent migration from DTT to other platforms
BEST PRACTICE WHEN RELEASING SPECTRUM TO LTE
Success factors to protect TV viewers •
A skilled mitigation organisation
•
Requirement that DTT stakeholders and MNOs cooperate
•
Right choice of filters
•
Ways to assess possible LTE issues
•
Low threshold to send and install filters
•
Other mitigation methods (at the user or the base station)
•
Clarification on economical aspects (costs to be borne)
•
… It the regulator really mean to protect DTT, then all such aspects shall be mentioned in the license requirements… …prior to auctioning the spectrum!
CONCLUSIONS Simple messages your regulator need to be aware of
Yes, LTE is causing interference Filters are helping, overload is manageable Little transparency with regard to interference Cooperation between MNOs and broadcasters give more opportunity to avoid interference in the future DTT can only be safeguarded if sufficient requirements are specified on the license conditions by the regulator
LOOKING INTO FUTURE SPECTRUM RELEASE (700 MHZ)
Issues to be considered…
By your regulator…
•
Problems in 800 MHz will still be relevant in 700 MHz
•
Mainly antenna amplifier overloading and receiver blocking
•
Adjacent channel interference now caused by mobile terminals (difficult to assess and reproduce)
•
Sufficient time to allow cross-country coordination to avoid cross-border interference from DTT to LTE
•
Why neighbouring countries can’t use the same spectrum for different purposes (flexible allocation)
“Flexibility” is not an option (this has happened!) Coverage with Rec.1546-1%
31st
Until March 2015, Spanish DTT at 800 MHz created interference into 4G base stations in Portugal (and South West France)
Level (dBuV/m)
I/N (dB)
Distance 1546 – 1%
Distance 1546 – 10%
19,3
-6
219
171
25,3
-6 to 0
183
138
31,1
-6; X-polarity
148
109
37,1
0;X-polarity
116
83
Interference level (from ITU 2337) Maximum distance (km) inside Portugal
Coverage with Rec.1546-10%
Simulations show why LTE700 launch requires careful cross-border coordination and enough time
Norwegian DTT at 700 MHz will have an impact on 4G uplink into mobile base stations in Sweden and Denmark for many years
240 kilometers
Interference level (from ITU 2337) for 1% of time
LTE… Don’t plug and pray!
Where can I find updated information about interference? The UK 4G/TV Co-existence Oversight Board has meeting reports made publically available
