The following speakers gave presentations:

Why not restrict a WLL user to one or two cells as the exact location of user is known?

It is true that exact location of users is known and is constant, but the exact pattern of CDMA radio coverage cannot be instantly and continuously ascertained, and it is not constant. Unlike the general perception, coverage of base stations is not in any geometric pattern. Even if at a certain point and at a given time, the strongest signal is ascertained, it is bound to vary (cell shrinkage, presence of a vehicle nearby, construction of a building, etc.). Restriction of a user to any particular cell (cells) would result in frequent coverage problems for users.

What are the advantages of Limited Mobility?

The main advantage of the limited mobility is that the subscriber is restricted to services within one charging area so that he/she can move within defined geographical area. This provides service akin to wire-line service, where subscribers do not enjoy mobility. It also provides a separate tier of service which can be offered by carriers at a lower tariff rate.

In addition, the Government/Telecom Regulator can issue new mobile wireless licenses in order to increase tele-density in the country and provide telecom services while still not defaulting the old mobile licensing agreements. Limited mobility also provides a separate tier of service which can be offered by carriers at a lower tariff rate.

How is the Limited Mobility achieved?

Limited mobility is achieved by setting some parameters on the radio and the switch side as well as managing the handset programming.

What are the important parameters that need to be taken into account for achieving limited mobility on the radio side?

Typically, mobility is controlled by using system ID/Network ID (SID/NID) configuration parameters and preferred roaming list (PRL) entries in handsets in addition to neighbor list management from the network side.

Another important parameter is the Cell Identification (CI) which is uniquely assigned to each and every base transceiver station (BTS) cell in the Radio Resource Configuration.

The other significant method is through home location register (HLR) provisioning.

What are the important parameters that need to be taken into account for achieving Limited Mobility on the Switch side?

The important parameter is Local Area Identification (LAI) or User Zone (UZ) which could be assigned to a single or a group of BTS cells, the cell IDs which have already been defined in the Radio parameters. LAIs or UZs are assigned keeping in view the footprint of one charging area.

What happens to the phone when it enters the Restricted Areas?

The phone could neither make nor receive a call. The data service could also not be availed. Such subscribers, when initiate a call, are rejected by the mobile switching center (MSC) due to failure in authentication of the binding of CI (Cell ID) and LAI (Local Area Identification) in the system HLR database.

To what extent could the Limited Mobility be achieved?

Limited Mobility could be achieved down to the level of a single cell. This means that a subscriber can be restricted to avail services within the coverage area of one cell. However, as explained above, in a multi-BTS area this restriction will result in severe quality of service issues.

What problems do the phones face which are located on the boundary of the two areas such that one is restricted and the other is not?

The phones that are located on the boundary of two such cells will experience a continuous disruption in their services. This is due to the dynamic cell coverage (continuous shrinkage and expansion) property of the CDMA networks. At one instant the phone may fall under the coverage of the unrestricted cell and at the other it could fall under the coverage of the restricted one causing intermittent service availability.

How many multiple LAIs could be applied to a single user profile?

This parameter varies from manufacturer to manufacturer. Typically, this value is from 8~10.

What is a National LAI?

If a phone is given a National LAI then it could avail the calling and data services any where within the coverage area of the network. In other words the phone can avail services from any base station of the network.

If the phones located on the boundary of two cells having different tariffs get coverage from both, what tariff would be applied during a call?

Tariff is applied on phone number not on a cell. Although different cells could have different tariffs in the same area, a subscriber should be charged based on his service agreement and the tariff should not be based on which cell provides coverage during the call.

Recommendations

Conclusion

Regulation should solve the gray areas like customers entering in other cells keeping in view the principle that “any policy which challenges human ingenuity is bound to fail specially, when it challenges the cash flows”.

Abdul Samad’s discussed the following:

WLL is an emerging technology which is technically similar to mobile telephony but used to provide conventional wire line installations or fixed services. Some of the technologies are basically developed for mobile telephony but with some control/modification are also used for WLL services with limited mobility. Because of “last mile” problem in the fixed networks, WLL is becoming popular. Its popularity is even more pronounced in the emerging market like Pakistan where the tele-density is very low.

Keeping in view the advantages of the WLL technologies and low tele-density of our country, the PTA as per the Government policy directives, auctioned available spectrum for WLL services. WLL operators will be able to quickly deploy network all over the country and provide telecom services to the far flung rural areas and increase tele-density. To address the concern of the mobile operators, WLL mobility has been restricted. WLL operators will have to satisfy the following conditions:

Ensuring limited mobility

Discussion

The following points came out during the discussion session:

(i)                Although the policy envisages that WLL operators will provide mobility only in their respective geographic areas for which licenses have been issued but, the CDMA technology can be used the same way as used by mobile cellular operators. Therefore, PTA will have to employ an effective monitoring mechanism to prevent the WLL operators from jumping the legal limits.

(ii)              Separate licenses for mobile cellular and WLL services should not have been issued. There should have been unified licensing as has been done in India.

(iii)             WLL technology will facilitate an increase in the telephone density and will help bring the rural areas into the mainstream of communications.

(iv)            The mobile cellular operators will also be reaching out to the underserved and unserved areas.

(v)             According to the PTA representative, the WLL operators will have to satisfy the following conditions:

(vi)            Any infringement of legal limits by WLL licensees will have serious negative commercial effects.

(vii)          With the equipment available in the market, service users can obtain access to cell outside their geographic areas. This can be done with or without the connivance of WLL operators.

Recommendations

On the basis of discussion and the views expressed by the participants, SDPI made at the following recommendations for consideration of the Ministry of IT and Telecom and the PTA:

(i)                 To bring unserved and underserved areas into the main stream of communications and to reduce the “digital divide”, the adoption of WLL technology is a positive step.

(ii)               The CDMA technology which support both the mobile cellular and fixed line services has its pros and cons. On the pros side, both the services can compliment each other and on the cons side the WLL operators can infringe on the interests of mobile cellular operators. Therefore, the adoption of WLL creates challenges both for the service providers and the PTA.

(iii)              The regulatory restrictions placed on WLL licensees namely: customers cannot authenticate or use their terminal equipment with the communication system of another licensee; a customer’s terminal can obtain access to the service using a single predetermined cell having a maximum radius up to local call charging area; and no inter-cell handover and roaming with other networks will be allowed can perhaps be workable in isolated single cells. Such regulatory restrictions will be very difficult to apply where contiguous cells would operate because of the following limitations of CDMA:

(iv)             The CDMA technology will not be optimally effective in restricted mobility.

(v)              There have been numerous cases where some unscrupulous persons operated clandestine telephone exchanges to mint money. As such, enforcement of laid down conditions could prove to be a Herculean task. Therefore, the principle that “any policy that challenges human ingenuity specially, when it challenges the cash flow is bound to fail”, becomes significant. Hence, a foolproof system of implementation will be the need of the time.

(vi)             With the convergence of various services and the difficulty in restricting mobility, a unified licensing policy, as adopted by India, will be the right thing to do. In fact, we should benefit from India’s experience.