LTE Implementation, Experience and Plans at Hutchison Drei Austria

Hutchison Drei Austria (H3A) belongs to the Hutchison Whampoa Limited Group. The Group is Hong Kong based, and mainly owned by Sir Li Ka-shing. In the telecom part, there is the Three Group in Europe and additionally operations in Hong Kong, Macao, Indonesia, Vietnam and Sri Lanka. The Three Group in Europe consists of the operations in Sweden, Denmark, Ireland, Great Britain, Italia, and Austria. In Austria we launched 3G services in 2003. We didn’t build up an own 2G network, but we used national roaming to complement our network. Beginning of 2013, we acquired Orange Austria. With the acquisition we now have more than 3.6 million customers.

Traffic Development

Last year, the traffic volume handled by our mobile network was about 10 million Gigabytes per month, meaning that on average each customer used some 3 GB per month. There are three mobile operators in Austria. In terms of subscribers, we are the smallest, but in terms of transmitted data volume, we have the biggest share. 62% of the overall data volume of all the Austria operators is carried by our network.

Frequency Assignment

Now we come to the network part, starting with the frequency assignment as the basis for our LTE deployment. We have frequency spectrum available in several bands. Our main focus concerning traffic volume and connected customers still is 3G. We operate 3G in the 2.1 GHz band (band 1). We have 2×25 MHz available in this band. But LTE is becoming more and more important. Our main deployment of LTE is in the 1800 MHz band (band 3). Currently we have 2×30 MHz available in this band. This band was formerly used for GSM only and we started to re-farm it to LTE last year. We cut down the GSM spectrum from 2×30 to 2×10 MHz, and we are currently implementing 2×20 MHz LTE in this band. Further in the 2.6 GHz band we have assigned 2×25 MHz FDD frequencies (band 7) and 25 MHz TDD spectrum (band 38). Beginning of next year we will additionally have available 2×5 MHz FDD spectrum in the 900 MHz band (band 8).

Network Consolidation and Modernization after Acquisition of Orange Austria

In 2013 we acquired Orange Austria. The legacy Hutchison network consisted of 4000 sites. In the years 2009 and 2010 we swapped out our legacy vendor equipment and implemented ZTE equipment on all RAN sites and in the core network. We covered 94% of the population with 3G in the 2.1 GHz band. Each of the 4000 sites was equipped with 3G equipment and we also had started to implement LTE. By the end of 2013 we covered 28% of the population with the 2.6 GHz FDD network.

The legacy Orange network consisted of 4600 sites, covering a population of 98%. Almost each site had 1800 MHz 2G deployed. Orange covered a population of 73% with 3G. Beginning of 2014 we have started to merge the networks. We are building one network from the two networks and the target network will contain 6000 sites. We have an increase of the site number for both customer bases by almost 50%. The overall number of sites is reduced by 2600 sites which results in a significant opex saving. 98% of population will be covered after merging the two networks.

We are currently implementing 2G, 3G and 4G on each site of the network. We selected ZTE as vendor for all three RATs. 2G is implemented in the 1800 MHz band with 2×10 MHz. We are deploying 3G in the 2100 MHz and 4G in the 1800 MHz band. As mentioned before, our 2.6 GHz FDD network covers 28% of the population mainly in high traffic areas. We are continuing to roll out 2.6 GHz according to traffic demand if the capacity of the FDD 1800 MHz LTE is exhausted. Additionally next year, we will start to implement LTE in the 900 MHz band for coverage enhancement.

LTE Implementation

The 1800 MHz band is our main LTE band. We implement it on all sites of the network with MIMO 2×2. With this configuration and 2×20 MHz spectrum the peak data rate in the downlink is 150 Mbps. The uplink data rate is up to 50 Mbps. We deploy Uni-RAN equipment from ZTE and we use multi RAT radio units for LTE 1800 MHz and GSM 1800 MHz which simplifies the structure of the sites and saves costs. Further we use a one antenna per sector coping with 1800 MHz and 2100 MHz. Additionally, the 2.6 GHz band is focused on capacity. In this band, we also implement 2×20 MHz FDD with MIMO 2×2 and achieve the same peak data rates as in the 1800 MHz band. For voice service currently we use CSFB. The next step we will implement VoLTE.

LTE Performance

From the speed tests performed by customers with the OOKLA speed test application, we can see the median downlink throughput on our network is close to 50 Mbps, the median uplink is about 25 Mbps and the latency is 30 ms. Currently we have some 25% of the overall traffic on LTE, so still the major part is on 3G. We expect that by the end of this year, the traffic on LTE will overtake the 3G traffic.

LTE Potential

There are several options within the next years to improve LTE QoS and to enhance capacity to cope with the increased demand from customers. As first step we may implement carrier aggregation of the bands 1800 MHz and 2600 MHz. This would increase the peak date rates up to 300 Mbps in the downlink and will improve efficiency.

Another possibility to enhance capacity is to roll out the 25 MHz of the 2600 MHz TDD band. According to the experience of other operators it is necessary to install separated antennas for FDD and TDD 2600 MHz. Potentially in downlink only usage of TDD is an option to use one antenna for both 2600 MHz bands.

A further option to increase capacity is the implementation of MIMO 4×4. Additional antennas and additional radio equipment would have to be installed. Up to 600 Mbps in downlink could be reached with carrier aggregation in combination with MIMO 4×4.