Nokia is trying to convince firms with a high proportion of mobile workers that supporting both fixed and mobile infrastructure is unnecessary, and often more expensive than supporting a single system.
When an enterprise has both fixed and mobile telephones, the amount of expensive inter-network traffic is often unnecessarily high, according to the mobile giant, and costs more than calling within one type of network.
The sectors where Nokia claims it has a good case include advertising, finance, healthcare, retail and wholesale, transport, media, utilities, manufacturing and public administration, where a high proportion of staff use mobile phones as much as landlines.
In addition to call cost-saving opportunities, further savings opportunities arise from being able to minimise or even remove capital and operational expenditure related to private branch exchanges (PBXs), the company said.
"What we're saying to IT managers is analyse the cost of your PBX, stop thinking of it as part of the building," Mikko Seppäläinen, head of mobile business voice at Nokia Networks, told vnunet.com.
Nokia argued that this analysis would show more inter-network internal calls than might be expected. Under some circumstances, it might even be simpler just to equip the workforce with mobile telephones.
And the fact that fixed-to-fixed internal calling is in some cases free of charge is given too much emphasis. In an organisation that has both fixed and mobile telephones, the proportion of fixed-to-fixed internal traffic is often surprisingly small, the company said.
When 61 per cent of staff have mobiles, Nokia's studies suggest, it becomes less expensive to move to mobile-only for voice.
But Nokia's attempts to convince businesses to swap from fixed lines to mobiles may not be compelling yet, especially without mobile operators cutting call costs.
And the analysis fails to consider the benefits of network convergence and VoIP.
"I accept the dual infrastructure argument would make some savings, but carriers like BT are offering exceptional deals at the moment and I can't see how mobile-to-mobile could be cheaper than fixed-to-fixed," said Keith Humphreys, managing consultant at EuroLAN Research.
A better idea might be Wi-Fi-enabled mobile handsets that combined with VoIP networks, he added.
Nokia believes much cheaper mobile calls are possible if operators are willing, and says enterprises negotiate tariffs with service providers.
"The mobile operator/service provider has a great degree of control over the total case and whether cost savings can indeed be realised in enterprises," its report states.
"Clear win-win potential exists in many cases. Mobile operators and enterprises can negotiate tariffs that both are profitable to the mobile operator and enable the enterprise to save costs by migrating traffic to mobile."
But while Nokia admits that per-minute tariffs have a decisive impact on whether enterprises should migrate traffic to mobile, it is difficult to imagine them slashing prices.
Earlier this month, a new report from analyst The Yankee Group again urged operators to forget about aggressively targeting fixed line operators. "Mobile cannot compete with fixed on price or performance, especially for data," it said.
Analyst Ovum also predicted that price differentials will remain.
"Mobile prices are typically two to four times higher than fixed. Both mobile and fixed prices will continue to fall. But we think the ratio between them will remain significant," said Julian Hewitt, chief analyst at Ovum.
Ovum acknowledged that 3G could bring prices down a lot faster. But Hewitt added: "On balance, we don't believe this will happen. It's not in the interests of the mobile operators to reduce prices rapidly and destroy their margins."
And with hefty 3G licences to pay, operators seem more interested in revenue optimisation and bringing more data content services to market rather than landline displacement.
So without more aggressive pricing from the operators, Nokia's case begins to unravel.
The operator may have the technology for fixed-to-mobile substitution, but with VoIP a favoured option within enterprises it may have a battle on its hands even to convince operators to offer businesses the choice.
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