Sunday, 5 May 2013

Challenges in LTE Network deployments

Challenges in LTE Network deployments 4G Long Term Evolution (LTE) technology is often touted as the magic bullet for operators worldwide to address the increase in data traffic on their capacity constrained mobile networks.

As new technology the LTE promises significant advantages over the current 3G technology such as higher spectral efficiency, lower cost of data transmission, faster speeds and lower latencies. However, as with any new technology, there are several challenges ahead for global operators in deploying 4G LTE networks.

So what are these challenges?

Fragmentation of LTE Spectrum and impact on number of site

The key feature of LTE(OFDMA) to handle multipath propagation without complex receivers but high variations in the amplitude of signals reduces the efficiency of transmitter power amplifier, warranting high quality of installation and accuracy .The majority of the spectrum allocation is in 2.6GHZ in large part of the world which is required to be harmonized .

According to study in different countries, the biggest single problem faced by operators is the range of spectrum bands to support.

The fragmentation is worse in other countries such as the USA, where within the same geography, telcos operate on different frequencies. Verizon and AT&T use the 700MHz band for their LTE networks while Sprint is using 1900MHz and 800MHz spectrum.

A lower spectrum band (e.g. 1800MHz) provides       better indoor signal strength and travels further compared to one of a higher spectrum band (e.g. 2600MHz). However, the higher spectrum bands are better suited for covering densely-populated areas and managing heavy data volumes due to their larger bandwidth.

The lower frequency spectrums are more affordable to build and signals travel further, whereas higher frequency spectrums require a lot of base stations to cover a similar distance. This could very well be another possible reason why different telcos around the world use different spectrum bands, besides the obvious fact that they are also limited by the availability of these bands.

2) Building a new and interworking with current network

Another challenge is how operators build up the network. Some carriers like to will build a completely new 4G network along the existing networks. Other telcos will create a converged network, where they try to make the different generations of technologies work together.

In both cases, the process is highly complex and cost intensive. The transition to 4G network will require new radio access technology and core network expansion, while maintaining existing 2G/3G networks alongside the new 4G network will result in additional burden on telcos.

3) New IP transmission al IP architecture

Need to create high capacity IP core network to connect MME(mobility management entity) ,S-GW,P-GW.EPC core network is to be dimensioned for high throughput and low latency for RAN.

All the interworking nodes including non3GPP systems is to be re-dimensioned. There is a need to reduce Round trip delay which requires the operator to look into its legacy IP network

4) Impact on Transmission and radio access network

While IMS is recommended by 3GPP,the lack of maturity and proven deployment in large scale is a big challenge in deployment of IMS operator .On transmission side the major area concerned will be:

  • Operator SDH/IP strategy swap plan.
  • Impact on existing network& conversion on IP transport network.
  • Economic use of backhaul capacity.

5) Return on Investment (ROI) on 4G LTE

As mentioned earlier, the migration to LTE or upgrading of existing mobile networks will incur high costs. Moreover, 4G LTE is expected to disrupt the traditional business models of telcos: voice calls and SMS.

6) Tiered Data Plans

To justify the investments in the new 4G networks, telcos have to change their data price models.

First, telcos can charge higher prices for their LTE offerings compared to their existing mobile data plans and maintain a higher quality of service to justify the higher premiums.

Second, They should implement "pay-for-what-you-use" pricing models, where consumers are charged based on their usage behaviours.

Third, Guaranteed speed, telcos can adopt a value-based pricing model where consumers can pay a premium for a better experience

7) True 4G Global Roaming - Fiction more than Reality

Due to the lack of harmonization of LTE spectrum bands across different countries, it is almost impossible within the near future to support LTE global roaming.

To use a LTE device for data roaming, based on the current worldwide spectrum usage, Wright said that the device needs to support at least 15 bands. From an engineering perspective, supporting so many bands on a device is really tough. Therefore, Wright believes that for the next decade, 3G data roaming will still be dominant.


In reality it comes out to be that multi technology hybrid complex network will exists in future and will continue for some time, the operator has to have a multitude of technologies and resources to manage the operations.

LTE will be rolled out in the phases which will lead from 200mhz to 2000mhz bandwidth implementation in due course of time to give the consistent time upgradable high capacity technological advantage and sustainability to deliver a seem less service experience operator have to interwork a strategy to manage the technology and network resources for providing end to end service assurance across multiple domain of the network.