Over the past ten years mobile communications have transitioned from a luxury item to a utility as critical as electricity and water. With this rapid expansion of subscribers and services, the operators of the wireless networks are making money today and adding subscribers at rapid rates. India for example has growth between 20% and 30% year over year growth in mobile subscribers.
However, this very success carries the seeds of potential crisis as these subscribers begin expecting, demanding and consuming ever-increasing amounts of data over these same networks. 3G networks-from the RAN architecture to the synchronous transport-were designed primarily to support increased voice capacity with a modicum of data support. They were never intended to support the multiple terabytes being transported today. HSPA and HSPA+, while definitely providing enhancements, are still bound by the 3G architecture and can be considered mere band-aids as opposed to long term solutions.
As operators eye the incredible growth and hence strain on their networks, they must ponder the question: When and how do I make the move to 4G? It's no longer a question of 'if', but more a question of "when" and "how".
It's Not a Technology Decision, It's a Business Decision
With all the claims being thrown about over how many megabits per second can be achieved with WiMAX and LTE, there is a tendency for operators to get caught up in the technology hype. This can be a dangerous position. While technology is relevant, it should not determine the driving criteria by itself. When it comes down to how many bits/second/Hz WiMAX or LTE can provide, fundamentally they are both limited by physics. Both technology camps use the same techniques to enhance capacity and an objective apples-to-apples comparison delivers similar performance.
Other parameters that should be considered before making a decision of WiMAX vs. LTE need to be considered. Each of the following questions and considerations has a major impact on the eventual success of the operator's business case:
- What frequency band will be used for the network? Is it a standard band for either technology?
- Will you need to make a cutover to 4G or do you have enough spectrum to do an overlay a la Verizon and ATT with their 700MHz holdings?
- What services are being targeted? Do your subscribers look for basic email and internet access or will they be driven by high bandwidth applications like Streaming Video, Video Conferencing, Online Gaming?
- This in turn will determine what types of devices will be used on your network. Just phones? Data dongles? Laptops with connectivity built in? Will Machine to Machine be a part of your device strategy?
- These two factors will in turn drive capacity. One of the key changes for operators is the shift from the network being coverage limited to being capacity limited.
- An operator must determine if data roaming is something their subscriber base is expecting. This in turn can be broken down to a question whether local roaming on competing local networks is more important than roaming internationally.
- Probably the most difficult decision to make is the question of when to make the move. The timing of the move must be done carefully, as it has the potential to have severe negative impact to the bottom line if handled poorly at the wrong time.
Whether the operator is considering moving from 3G to WiMAX, 3G to LTE, or even WiMAX to LTE, they need to develop "transitional business cases" and be able to see the financial impact of such a transition. Ultimately all of the factors cited above have to be considered and factored into a business model where clear financial results can be predicted.
Business Case for a Transitional Network
Taking into consideration the factors listed above, integrating such technical parameters as terrain and equipment performance, and deriving the relevant financial results are not easy tasks. The right business model will allow the operator to adjust Key Performance Indicators (KPI) and see the immediate impact on the finances. The WiROI tool from Wireless 2020 is just such a tool and has been used to assist operators with decisions such as this in over fifty networks worldwide.
The tool incorporates technical performance of a given vendor's system, factors in market and subscriber data, applications, devices, and more-up to 300 input parameters-to deliver full and complete financial projections. With the WiROI tool, an operator can compare all three transitions mentioned previously:
- 3G to WiMAX
- 3G to LTE
- WiMAX to LTE
The result is a user-driven GUI with detailed financial numbers that can be used to help in this critical decision of what, and maybe more importantly, when to move forward. Figure 1 shows the results for a TD-LTE deployment in Malaysia. This depicts the results of a WiMAX license holder deploying TD-LTE in partnership with mobile carriers.
Making the Call
The rise of mobile data is undeniable. One can argue how much data a 3G network can support and when it will run out of capacity, but eventually the 3G network will run out of steam and the operator will be required to transition to 4G. With the "battle" between WiMAX and LTE increasing with each day, the rhetoric from both camps is in full swing. For an operator today running a successful 3G network, sifting through the competing claims can be daunting. It is easy to get lost in how many dB here or there this or that system can deliver.
But in the end the decision by an operator must be made from an integrated business and financial perspective. As this decision will have a far-reaching impact on the viability of the operator, it is imperative that they have all the data at hand. Being able to model varying approaches and including the factors described above are essential for an operator in order to have confidence in the anticipated results. While this is probably the biggest decision an operator has to make, it does not have to be done blindly. Using tools such as WiROI can help make this decision with eyes wide open and full knowledge of the totality of potential impacts-from the minor issues to the most important ones.