Missed Call Problem – A TRIZ Approach
Recently my friends (Vishwa and Vijay) and I ( I know “I” seems odd but MS Word wont let me have it otherwise and yeah I know its PROPER English 
) were discussing a problem that that’s having a detrimental effect on the sleep patterns of a lot of engineers and managers in the mobile phone industry.
The Problem can be stated as “The Missed call facility along with the Caller line identification feature is being misused by the customers by using the same to avoid making revenue generating calling.”
The main challenges accompanied with the problem is that
- The problem in itself is not explicitly illegal/ unethical from the customer view point to solve by any legislation.
- Any penalty/cost to be imposed on the missed will also be inadvertly penalizing the people making “genuine” missed calls.
- A lot of customers with intent to make revenue generating services are not getting access to the system which in turn is costing the company invisible revenue loss.
- The solution for the 3rd problem requires investment for a larger infrastructure than what is not financially justified by the actual “active” customers in the network based on the current revenue model
Now to apply the TRIZ contradiction matrix to this problem, it needs to be stated as a contradiction.
There may be multiple ways of stating the problem as a contradiction but I take up this specific way -:
Say you improve reliability of the network by limiting the total number of users as stated in the 4th challenge then the worsening quality is that the quantity of connections that can be offered with the same infrastructure is reduced and consequently revenue is affected.
Or in TRIZ terms it can be stated as
Improving Feature: Reliability Vs Worsening Feature: Quantity of the substance
This is a very abstract way of representing the contradiction but TRIZ is after all an abstraction
The solutions can be looked up at http://www.triz40.com/
Solutions are
21. Skipping
- Conduct a process, or certain stages (e.g. destructible, harmful or hazardous operations) at high speed.
28 Mechanics substitution
- Replace a mechanical means with a sensory (optical, acoustic, taste or smell) means.
- Use electric, magnetic and electromagnetic fields to interact with the object.
- Change from static to movable fields, from unstructured fields to those having structure.
- Use fields in conjunction with field-activated (e.g. ferromagnetic) particles.
40. Composite materials
- Change from uniform to composite (multiple) materials.
3. Local quality
- Change an object’s structure from uniform to non-uniform, change an external environment (or external influence) from uniform to non-uniform.
- Make each part of an object function in conditions most suitable for its operation.
- Make each part of an object fulfill a different and useful function.
Now the theme among most of them is the break up the service especially looking at the rule “Change from uniform to composite (multiple) materials.” (The quantity here being the number of connections as defined by us earlier) or from all 3 rules in “Local Quality”.
Now translating this into terms specific to our problem we can come with with- :
Provide different services with different QoS but at corresponding costs. As in, provide two or more separate networks, one that has a poor QoS but also has a much lesser “infrastructural cost” to be levied from the customers and provide another high quality network where the cost of service is higher but QoS is better.
This may at first glance seem to penalize the people who would be responsible for generating revenue even in the first case. But only by going into the actual financial details can we ascertain whether these new networks would exist at a higher cost segment or in the similar band as to now. (The lower QoS network might even get cheaper)
In one way I had always this solution in mind and probably that why I was able to see thru the esoteric solutions given by TRIZ, but then again innovations ultimately has to come from the Innovator: P
Now the funny part -: This already exists! In a way that is…
Take the case of Bangalore
There are three prominent GSM providers -:
Spice Hutch and Airtel.
For people who have experience with the networks they can see the semblance between spice with the first network (extremely low cost but not that great QoS), Hutch ( Low Cost and decent enough QoS) and Airtel ( the costliest of the lot with probably the best QoS)
…But in one sense, the last para seems skewed from the actual solution da.. It is true that you have different kinds of networks with different QoS and costs.. But the solution holds good only if the different networks are offered by the same provider.. Get the idea? Only then can that provider strike a balance between the missed calls and the genuine ones he supports..
But the idea sure is innovative
Comment by Vishwa — August 30, 2007 @ 2:59 pm
I understand that it’s not totally the same. But like I said solution is similar only in a way
Also like its being practically proved by the providers each in itself is a sustainable business model
Comment by cafm — August 30, 2007 @ 3:00 pm
Are you sure the network providers have not employed this concept? They may be placing all the low revenue generating customers ( higher % of the pre paid customers and smaller % of post paid customers) in the same bandwidth range and have a separate BW for others. At least they would have weighed in the advantages/disadvantages of adopting this.
The 80-20 principle kicks in here I suppose. 80% of the customers might be in the lower end and 20% in the higher end. So this kind of solution might lead to the frustration of almost 80% of the customers and the QOS for them might be totally unacceptable (say 80% of the customers fight for 20% of the BW). In real life, the poor fight for the morsels and the rich enjoy feast after feast. But employing the same concept in technology might be conceived as a sin since a major portion of the BW is not being properly utilized.
But if everyone uses the same QOS, no one will be excited about the QOS but it will at least be “acceptable???. Take the case of a parliament or UN assembly. Either the state with greater population is represented in greater number (or) there is an equal representation immaterial of the size. But our solution is like proposing a parliament where greater the riches, the more representation you have.
So, I am just wondering whether employing this type of a solution will do more damage than desired.
Your observation that different service providers provide different QOS is very good though. Maybe they are all in a pact (like politicians splitting portfolios among themselves)
Comment by Vijay — August 30, 2007 @ 3:02 pm
Hi Vijay,
As far as I know I don’t think its employed by the same Network…yet
There was a ….???Socialist??? (for lack of a better word) sentiment through out your mail.
See I understand that what you are saying is proper from a general point of view. But this is not a state run hospital; it’s a service being provided by company that’s there to make profit. And if you pay more you get better service. The “acceptable??? QoS and current revenue is not satisfactory, hence the birth of this problem rt?
Also we are not stretching the QoS and cost to limits as in one with have absolute impeccable QoS with equally high costs while other has the worst QoS and low costs . They will be different but not too far apart since in a country like India if the higher Quality network were to really high there would not be enough takers to make it economically viable.
Its common sense that the capability of a network must always be as high as demand during the peak hour. This is generally calculated using certain formula which would then try to factor in the no: of active connections. These formulas would use certain proportionality constants to account for the same which are derived based on the past statistics. I am suggesting that we play around with these factors between the networks
And in case the demand for either of the networks is less, it would die a natural death without casing financial loss to the provider since infrastructure of the dead network can still be used for the other….
Comment by cafm — August 30, 2007 @ 3:04 pm
got the point…
Say we have 2 queues and provide “tokens??? for the highly valuable customers
Queue 1 -> those with no tokens get here
Queue 2 -> those with tokens get here
Queue 1 leads to a BMTC bus in which you stand and ride
Queue 2 leads to a BMTC bus in which you sit and ride
Queue2 folks do not enter Queue1
But Queue1 folks can enter Queue2 if it not crowded
Most times, Q1 will be more crowded than Q2
A common scenario: Some Q1 folks have infiltrated into Q2 and making best use of the services since the Q2 folks are not using it anyways. Then Q2 folks come in and find that their seats are already taken. Maybe they can ask the Q1 folks to get up. Unfortunately, such a “pre-emption??? policy cannot be adopted for mobile users. How can this be overcome? You allow the Q1 users to get into Q2. But is there any way to ensure that they get out in time so that the Q2 folks are not disturbed?
Comment by Vijay — August 30, 2007 @ 3:05 pm
This seems to be a build up on the original idea to ensure proper utilization of resources rt?
From what I know of the GSM technology you cannot “push out??? people and also dynamic allocations of channels is already done using a already complex algorithm taking into account nearest tower, environmental factors etc
The takeaway is I feel once your in a same network (“Q2??? buses) it would be hard to distinguish between the token carrying and other customers, and it would require a revamp of the whole systems.
Comment by cafm — August 30, 2007 @ 3:06 pm
I know that you can’t push out ppl. So you need to arrive at a probabilistic pattern to determine time-based probability of arrival of high priority users (say P1) such that you do not allow the lower priority ones to get into the high QOS NW in the first place, if P is higher than a certain limit.
But again, it is very possible that the time-based probability of arrival of low priority users(P2) is a similar to P1. In this case, we will still be left with the problem I previously mentioned.
Comment by Vijay — August 30, 2007 @ 3:07 pm
Hmm…
See in terms of the technical implementation of the original idea, I was thinking more in terms having a completely different Control channels so that they act like independent networks.
And since the peak usage patterns of the both of the networks would be similar, I feel if the design is proper, there won’t be any wastage of bandwidth since when the high quality network would be already be full or nearly full when the low quality network is also reaching its limits
Comment by cafm — August 30, 2007 @ 3:08 pm
Or rather the low quality one would already be overloaded by the time the high quality one is starting to touch its limits…
Comment by Vijay — August 30, 2007 @ 3:08 pm
See that’s the price…they pay…or don’t pay rather…. For the quality….
Also since connection is not a continuous thing and assuming 2-3 min average call duration… and even less for missed calls… there wont be total denial of service to any particular user….
Comment by cafm — August 30, 2007 @ 3:08 pm
Ya… I was just correcting the last statement of yours
But I still have my doubts about the “total denial of service??? part… the low paying customers will be affected by total denial of service -> at least more often than in the current implementation, given the same total available BW… and I am not being “socialist??? or anything… it is just that ppl may not really go in for the low QOS offers
I am not totally convinced about there being only a slight between the QOS of the two NW… to achieve our purpose, there must be a significant difference… this must be quantifiable… say the high QOS almost never gives a NW busy msg and if it does, it is only for a few seconds whereas a low QOS gives this msg more often and for a more prolonged duration, say 3 minutes ( I am a hutch user and I get the msg sometimes for about 1 minute )
Comment by Vijay — August 30, 2007 @ 3:09 pm