MMDS vs LMDS
This page on MMDS versus LMDS describes MMDS and LMDS basics and provides difference between MMDS and LMDS.
MMDS
MMDS stands for Multichannel Multipoint Distribution Service.
It is used as replacement of cable TV service provider.
MMDS is used to cover rural areas where it is not possible
to reach by broadcast and cable TV operators.
Refer MMDS Architecture➤.
LMDS
LMDS stands for Local Multipoint distribution service.
It is used for providing TV and 2-way internet service similar to MMDS.
Refer LMDS Architecture➤.
Frequency allocation for MMDS/LMDS
2.15 GHz to 2.68 GHz frequency band is allocated for MMDS; five of the bands in these bands are already used in USA. OFDM modulation technique with bandwidth of 6 MHz composed of 512 sub carriers is used for MMDS. The sub carrier spacing is about 12 KHz. It is also used for providing 2-way broadband data or internet service.
About 30GHz to near about 40GHz bands are used for LMDS. Mainly used in USA, Europe and other countries.
Comparison between MMDS and LMDS
This section describes merits and demerits of MMDS and LMDS and also mentions similarities or difference between these technologies.
>> As mentioned both are used for TV and 2-way internet service using fixed wireless access.
>> Due to lower RF frequency range MMDS provide lesser BW compare to LMDS. Higher data rates are also going to be achievable owing to OFDM technology advancement with MMDS. But MMDS is ideal for small business enterprises and residential users and LMDS is used for larger businesses. LMDS offers higher data rates.
>> MMDS signal can cover long distance and hence used in large cell network scenario. LMDS signal can cover short distance from Base Station equipments.
>> Due to larger wavelength MMDS signals are less susceptible to rain and absorption losses compare to shorter wavelength LMDS signal.
Let us summarize tabular difference between LMDS and MMDS below.
| Specifications | LMDS | MMDS |
|---|---|---|
| Full Form | Local Multipoint Distribution Service | Multichannel Multipoint Distribution Service |
| Architecture | The LMDS architecture consists of NOC (Network Operation Center), BS, CPE and Fiber backbone. It has cellular like architecture. | The MMDS architecture consists of tall antenna tower, backbone internet connectivity using router and network management system. It has microwave link like architecture. |
| Frequency of operation | 28 GHz, 36 GHz | 2.5 GHz, 3.5 GHz |
| Network Topology | P2MP (Point to Multi-point) | P2P (Point to Point) |
| Distance coverage | Good more smaller distances. (2 to 8 Km) | Covers larger distance. (50 to 100 Km) |
| Number of cells | more | very few |
| Data rate | 1 to 10 Mbps | upto 2 Mbps |
| cost | CPE cost and deployment cost is medium to high. | CPE cost and deployment cost is low compare to LMDS. |
What is Difference between
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Difference between SC-FDMA and OFDM
Difference between SISO and MIMO
Difference between TDD and FDD
Difference between 802.11 standards viz.11-a,11-b,11-g and 11-n
OFDM vs OFDMA
CDMA vs GSM
Bluetooth vs zigbee
Fixed wimax vs mobile