Creating the Future Economically-Viable Networks

Emre Yılmaz, January 2017

Figure-1: The 5 Mb of data which was carried to a remote place by plane 60 years ago1. A speed test showing the capabilities

of the network: 383.10 Mbps (47.9 Mb per second, LTE Advanced network, 3 carrier aggregation 20+20+10 MHz, 880km

server distance): A huge time and cost savings in 60 years.

“At the beginning a disease is easy to cure but difficult to diagnose; but as time passes, it

becomes easy to diagnose but difficult to cure” says Niccolò Machiavelli in his masterpiece,

The Prince. The way of connections between people to people, people to things, things to

people, things to things are predicted to increase and diversify in the near future. Together

with increasing data traffic demand, our need for a new radio network system will be

necessary in order to meet all this diversified connection demands since their

requirements from the deployed network can be different from each other in terms of

throughput, latency, and energy.

An important point which should not miss is the economic viability of this new system.

Starting from the deployment of 2G to now, investments carried out by the network

operators have diversified and flourished. Income per megabyte has decreased and might

be in decreasing trend and be inexpensive for the vast acceptance of data usage for the

customers. If the network operators cannot provide avoidable prices for the data, the

predicted growths for data traffic could not take place and the growth of the networks

could be at the risk of entering a phase of stagnation.

For that matter, a new system for the radio network should give utmost importance to the

cost-reducing improvements and consider it as one of the main pillars of its capabilities.

1 Courtesy of IBM Corporation

I believe, the “disease” metaphor for the new radio network system which I quoted from

Machiavelli in the beginning of this paper is the cost problem of “a byte” from the network

operator side and how we can reduce it in the new network system architecture.

From now on, I would like to summarize my thoughts on future networks and how we can

ease the ways to solve crucial problems which will be burden to realization of the future

digital era.

In order to reduce the cost of a byte network operators seek to decrease operational costs

of the network. The network energy cost of a typical mature network is up to 15% of the

network OPEX 2 . My vision is from top to toe creating an energy efficient system

architecture which also will help to ease carbon emission of the networks.

1- The network systems should use energy saving self-optimizing solutions. It is

predicted that just 15% of the energy is used for transmitting bits on an operating

network. 85% of the energy doesn’t directly contribute to overall traffic3. So, the

management of the base station power should be smarter; the voltage-current

volumes and broadcasting power of the station should be managed by smart

optimizing solutions based on intelligent resource management under the

framework of the SON (Self-Organizing Networks).

2- Current practices show that the base stations are consisted of antennas (rooftop or

tower) and a sheltered system room where the baseband and other system elements

are insulated. The sheltered containers are cooled by cooling systems which

consume a great amount of electrical power. Structuring the new radio access

system with a new outlook will be beneficial. It is possible to redesign network

architecture by collecting all the base station elements besides antennas and radio

units at a close-edge network data centers. Eventually the cooling requirements of

these system blocks could have been done by a central management and dozens of

optimization processes could have been applied in order to reduce the energy

consumption of overall network.

2 GWATT 2015. “Global What-if Analyzer of Network Energy Consumption”, Bell Labs Research

3 Nokia Networks 2016. “White paper: 5G network energy efficiency”

3- Overall new energy-efficient hardware components and materials should have been

studied from top to toe, from access side to the core side in the new radio network

systems.

The second cost-reducing perspective should be built on radio access side.

The projected 5G deployments focus to radio access layer working on centimeter wave and

millimeter wave frequency bands in the electromagnetic spectrum. One of the crucial

advantages of these bands is their capability on high spectral efficiency. On the other

hand, the difficulty of this frequencies is their high propagation losses on the field.

Therefore, ultra-dense site deployment is needed in order the battle this challenge. From

the network operator’s perspective, the site rental costs are one of the main contributors

of the network OPEX. For ultra-dense site deployment, the operator needs to make more

and more site rentals. Without arranging the network tariffs, a rise in the percentage of

the site rentals in the network OPEX could be a burden to the economic viability and

compatibility of the network. The predicted ultra-dense deployment of the 5G system could

have been failed because of financial challenges the network operators will face in the site

rentals.

For these reasons;

1. In the radio access side, instead of planning a network needs ultra-dense site

deployment, 5G can be considered as a multi-tiered system where sub-6 GHz,

centimeter wave, millimeter wave frequencies are in use and supporting each

other.

2. Even though 5G systems are considered as super-high frequency systems in the

radio access side, it can be predicted that they would evolve from the existing 4G

networks under the LTE projection. Alongside of capacity and high throughput

layer needs there should be an umbrella coverage layer need for this new system

which is based on digital dividend spectrum in order to support the whole order.

Separating the control plane from the data plane, supporting the control plane with

an umbrella coverage layer and SDN (Software defined network) structure could

be considered beneficial to achieving both the targets of the 5G -new radio network

system- and also reducing overall costs by decreasing the need of ultra-dense

deployment in order to building up a sustainable control plane.

3. Transition from the current advanced network systems to the new radio systems

(NRS) should be managed in a way which is beneficiary both for the customers

and the network operators. Today the most operators deploy LTE-Advanced

system where large bandwidths can be provided to the customers by carrier

aggregation technology which is able to combine 5x20MHz bands in order boost

user downlink throughput on capable terminals. Transmit diversity (and MIMO)

is also another capability which the system supports for the same reasons. In

practices these solutions have their return-of-investment limits since adding new

carriers and increasing the MIMO gain requires hardware necessities. Investing

in adding new components to the base stations could be a wrong investment

strategy on the edge of new radio systems. For the smooth and financially viable

transition of the radio networks, I summarized my approach for the evolution of

future radio network systems in the Figure-2.

Current networks hold HSPA and LTE at the same time as two emerging data-

centric technologies. Non-progressive GSM systems are not shown in the figures

below since the main focus is increasing data-traffic demand and voice traffic of the

networks could have been considered as stable in the near future. So the new

systems could easily adopt the voice-centric network needs.

Figure - 2 : My projection of the future wireless networks. HSPA refers to 3G systems, LTE : 3 GPP Releases 8 - 9 , LTE - A 3GP : P

Releases 10 - and NRS: New Radio System 12

HSPA

LTE

LTE - A HSPA

LTE - A

Sub 6

GHz NR S

LTE - pro

M ulti - tiered

NR

( )

HSPA

LTE - A

LTE - unlicensed

LTE - A

LTE - unlicensed

S ub

6 GHz &

30 GHz NR S

LTE - pro

M ulti - tiered

NR

sub6,30, 60 GHz

NRS (

LTE - A

Sub 6

GHz &

30 GHz NR S

Time

Sc

Phase - 1

Phase - 2

Phase - 3

Path - 1

Path - 2

C urrent Situation

o f

the

Commercial Networks

sub6,30, 60 GHz

NRS

In the near future, due to increasing data traffic (estimated as 10.000 fold within

the next 20 years by the Bell Labs) the capabilities of the network should be

advanced step by step.

For the next phase of the current network structure is two path available.

Implementing the new radio systems (briefly 5G) immediately or choosing another

way where the current LTE system can have more capabilities by unlicensed

spectrum. The latter one is consistent with the main idea of this paper since the

investment in new spectrums and the rollout of an entirely new radio system while

3 other systems still in use at the base stations as emission point will require new

investments by the network providers. Using unlicensed spectrum under the

framework of the LTE system could create a smooth transition to the future new

networks.

In the remaining phases, new radio system could have been deployed as a multi-

tiered way by advancing the hardware and structural capabilities of the system. At

the end LTE could evolve as LTE-pro where new radio core architecture can be

valid for it as well. An umbrella coverage component can be positioned in the LTE-

pro network for the control plane management and the massive IoT services.

Briefly, the communication links are the main pillar of the global economy. From the

railroad expansion in the late 19th century to the transatlantic fiber optic networks these

links helped to advance the economies. In the Figure-1 I made an analogy describing how

the advancing communication links created time and cost-savings for all of us.

Today we are on the edge of new digital era which the high-speed data networks will form.

High-speed data networks can be considered as emerging technologies, just in 20 years

they have dominated the world today.

It can be predicted that demand for these data networks and eventually the data traffic

overall will increase hugely in time. And the wireless systems will be diversified with a

variety of needs from customer’s side consist of low latency, ultra-high throughput and

massive IoT. In order to meet those demands network operators and the tech companies

will invest the new technologies just like as currently they are doing so. But as I did

remark in the first sentences of this paper with the metaphor I used by quoting

Machiavelli, in order to achieve viable, sustainable and secure growth of all the business

to decrease the cost of “a byte” is needed.

There are a myriad of opportunities and the areas of development if we consider the

possible developments of current and the upcoming new network systems holistically. And

there are lots of challenges to put these opportunities into reality: from the solving

interference problems in the LTE unlicensed band to separating the data and control

planes of the networks under the framework of SDN (Software Defined Networks) and

NFV (Network Functions Virtualization), from designing energy efficient optimization

processes with an advanced SON to the realization of multi-tiered networks providing

services at different spectrum levels with an enhanced spectral efficiency.

All of them need a systematic research and development process.