LONDON — To achieve higher download and upload speeds, vendors and cellular operators are planning to use a number of different technologies over the coming years in both HSPA and LTE networks.
At their core, many of these technologies are related to better coordination among base stations, and the introduction of smaller base stations to help networks keep up with an increasing volume of data.
However, many of these technologies will put even more strain on smartphone and tablet batteries. Another area where some smart thinking will be needed to ensure devices keep up with networks is antenna design.
“We have to trust that the technology will be improved” in these areas as well said Jan Färjh, vice-president and head of research at Ericsson LM.
1. Use multiple antennas at the same time
One of the key ingredients in the development of faster mobile networks is an antenna technology called MIMO (Multiple-Input Multiple-Output), which uses multiple antennas in the base station and on the device to send data.
Today, LTE (Long Term Evolution) networks use two antennas on the downlink, but future networks will at first be able to use four antennas, and then a bit further into the future eight. LTE networks that use the latter are already being demonstrated and can achieve speeds close to 1 Gbps.
The big challenge with MIMO is to fit all the needed antennas on the user device, especially on smartphones where there is little space to put them and still have enough distance between the antennas for the technology to be effective.
2. Use more antennas on the uplink, as well
Download speeds in mobile networks tend to get the most attention. But as more users upload information from mobile devices to cloud services and share photos via social networks, upload capacity is becoming more important, according to Ericsson.
Thanks to a technology called Uplink Transmit Diversity, users will be able to send data via two antennas to improve quality of the uplink connection and increase speeds or lower battery consumption, according to Jan Derksen , head of technical marketing at Ericsson Networks.
The improvements are achieved using the two antennas to aim the signal at a base station, a technology called beam-forming, according to Qualcomm.
3. Take advantage of spectrum in different frequencies
The speed a mobile network is able to achieve is closely linked to the amount of spectrum used; more spectrum equals higher speeds.
But spectrum is a limited resource, so the telecom industry has come up with a technology that circumvents that reality called carrier aggregation. The technology will allow operators to bunch together spectrum in different bands and use them as one data link.
At first, operators will be able to use frequency bands that are located next to each other, and then mix and match more freely, according to Färjh.
The idea of using spectrum in the most effective way possible can be taken even further by making all bands technology neutral, allowing operators to turn off the slower GSM network if there are no users that need it and instead just use LTE, Färjh said.
4. Download data from two base stations
Together with Qualcomm, Nokia Siemens Networks has developed Multiflow. The technology will allow mobile devices located close to the edge of a base station’s coverage area to connect with a second base station serving a neighboring area, as well, and download data from two base stations at the same time.
By deploying the technology in its network, operators can double the throughput for users at the cell edge, according to Nokia Siemens.
5. Better Wi-Fi integration
Operators are getting increasingly interested in using Wi-Fi to offload their networks, and in the process offer better overall network performance. The thinking is that users should automatically be connected to the network that offers the best experience.
Earlier this week, Wi-Fi Alliance started certifying products as part of the organization’s Passpoint program, which is based on technology defined in its Hotspot 2.0 specification.
Users will be able to authenticate themselves with a SIM card, just as they do on mobile networks. Therefore, certified mobile devices can automatically discover and connect to Wi-Fi networks powered by access points that have also been approved.
6. Use a mixture of small and large cells
The development of so-called het nets, heterogeneous networks, which use a mixture of traditional large base stations and smaller cells, placed in areas where there are a lot of users, will also be an central part of next-generation mobile networks.
At first, the small cells and the large ones will use the same frequency band, according to Färjh. But the industry has also started discussing the ability to use different bands for the small cells, including Time-Division Duplex (TDD) transmission 3.5GHz, he said.
TDD networks send download and upload traffic over one channel, and are, for example, a good fit for video streaming — since operators can choose to dedicate more spectrum to downlink traffic. In the small cell scenario, operators could create download zones with especially high speeds