1、 Demand analysis
The following core requirements exist in the retail chain store network and power supply scenarios, which are the core basis of the scheme design:
Unified power supply for multiple devices: stores need to supply power for high-definition surveillance cameras (10-25W/set), wireless APs (15-30W/set), POS cash registers (5-15W/set), electronic price tag controllers (3-8W/set) and other devices. The traditional distributed power supply adaptation has problems such as messy wiring and difficult maintenance.
Stable network transmission: POS transaction data (low delay required, packet loss rate<0.1%), monitoring video stream (1080P camera bitstream 2-4Mbps/channel), and wireless passenger flow analysis data need to be transmitted stably to avoid affecting the operation due to network interruption.
Centralized management: there are a large number of chain stores (usually 10-100+), which need to support the headquarters to remotely monitor the equipment status and configuration parameters, and reduce the on-site operation and maintenance costs (the frequency of single store operation and maintenance is reduced to less than once a quarter).
Redundancy and reliability: core equipment (such as main PoE switch and uplink) should avoid single point of failure and ensure uninterrupted system during business hours (usually 12-16 hours/day).
Cost optimization: it is necessary to balance equipment procurement costs, wiring costs and post operation and maintenance costs, and control the budget for network and power supply transformation of single stores within a reasonable range (small stores<5000 yuan, medium-sized stores 5000-10000 yuan).
2、 Principle of scheme design
Stability priority: industrial or commercial high stability PoE switches (MTBF ≥ 50000 hours) are preferred, and key link redundancy design is preferred.
Compatibility adaptation: support 802.3af/at standard (covering more than 95% of store equipment), and some high-end stores reserve 802.3bt (60W power supply) ports to adapt future high-power devices (such as 4K cameras).
Scalability: 20% -30% redundancy is reserved for switch ports (12/16 port devices are selected if 8 ports are actually needed), which supports elastic expansion of the headquarters management platform (no need to restructure the management architecture for new stores).
Ease of operation and maintenance: support Web visual management, remote operation and maintenance of cloud platform, and real-time push of fault alarm (such as port power failure, power overload) to the headquarters operation and maintenance terminal.
Green energy saving: enable intelligent power management (such as port sleep and dynamic power supply) to reduce energy consumption during non business hours (energy saving rate ≥ 15%).
3、 Core deployment scheme
（1） Equipment selection
Type selection according to store size, balance performance and cost:
Store Type
Area (m2)
Core equipment recommendation
Port configuration
Total PoE power
Applicable scenarios
Small stores
＜ 80
Gigabit unmanaged PoE switch (such as TP Link TL-SG1016PE)
16 ports (12 PoE ports+4 gigabit uplink ports)
370W
Community convenience stores, small specialty stores
Medium store
80-200
Gigabit network management PoE switch (such as H3C S5130S-28P-PWR-EI)
24 ports (24 PoE+ports+4 SFP uplink ports)
520W
Standard supermarket, chain clothing store
Large stores
＞ 200
10 Gigabit uplink PoE switch (such as Huawei CloudEngine S5735-L24P4X-E)
24 PoE+++4 10 Gigabit optical ports
740W
Flagship store of shopping center, large supermarket
Model selection supplement:
Wireless AP intensive areas (such as peak passenger flow areas): 4 PoE switches (such as Mercury SG1005P) are added for regional power supply to avoid overloading of single switch ports.
Low temperature/wet stores (such as cold chain area): select a wide temperature PoE switch (operating temperature -10 ℃~55 ℃) to prevent equipment downtime.
（2） Network architecture design
The three-level structure of "headquarters region store" is adopted to achieve centralized control and efficient local operation:
Headquarters layer: deploy core switches (such as Huawei S12700)+cloud management platforms (such as H3C iMC, TP Link Omada), responsible for unified configuration distribution, equipment status monitoring, and data summary and analysis.
Regional layer (optional, when there are more than or equal to 30 stores): deploy regional convergence switches to connect headquarters and stores through dedicated lines/VPNs to reduce the pressure on headquarters bandwidth (the bandwidth of stores in a single region is aggregated and then uploaded to the headquarters).
Store floor:
Main PoE switch: access POS machine (VLAN 10), surveillance camera (VLAN 20), wireless AP (VLAN 30), and uplink to store router (such as Huawei AR650) through gigabit optical/electrical interface.
Zonal PoE switch: if the store area is large (such as>150 ㎡), it is deployed according to functional zones (cash register area, shelf area, entrance and exit), and connected to the main switch through gigabit links to avoid long-distance wiring (the maximum distance of PoE power supply is ≤ 100 meters, actually controlled within 80 meters).
Architecture advantages:
Each VLAN is logically isolated, POS transaction data and monitoring data do not interfere with each other, improving security;
Uplink redundancy: The main switches of medium-sized stores and above are equipped with dual uplink connection routers to avoid single link failures.
（3） Power supply and bandwidth planning
Power supply planning:
Power calculation: total PoE power of a single store=∑ (number of equipment × single equipment power) × 1.3 (redundancy coefficient). Example: 10 cameras (15W/set)+3 APs (25W/set)+4 POS machines (10W/set), total power=(150+75+40) × 1.3=344.5W, select 370W and above switches.
Priority configuration: set POS machine and main camera as high power supply priority, wireless AP as medium priority, and electronic price tag as low priority to ensure priority power supply when core equipment is powered off.
Bandwidth planning:
Store uplink bandwidth: calculated as "monitoring bandwidth+POS bandwidth+wireless bandwidth", for example: 10 1080P cameras (3Mbps/channel)+4 POS (1Mbps/channel)+3 APs (20Mbps/channel), total demand=30+4+60=94Mbps, select 100Mbps dedicated line (small stores) or 1Gbps dedicated line (medium-sized stores).
Switch port bandwidth: access port gigabit (to meet single device peak demand), uplink port gigabit/10 gigabit (according to the store size), to avoid bandwidth bottlenecks.
（4） Management and safety design
Centralized management:
Cloud platform function: real-time view of the switch port status (PoE power utilization rate, port online rate), device alarms (such as port short circuit, power overload) of each store, support remote restart of ports, upgrade of firmware, and batch configuration of VLANs.
Data visualization: the headquarters platform displays the network health of each store (such as packet loss rate and delay), PoE resource utilization, and generates monthly operation and maintenance reports.
Safety protection:
Port security: enable MAC address binding, and limit the maximum number of access devices for a single port (for example, POS port is bound with cash register MAC to prevent illegal device access);
Access control: ACL rules restrict access between VLANs (such as prohibiting monitoring VLANs from accessing POS VLANs);
Encrypted transmission: The data between the headquarters and stores is encrypted through IPsec VPN to prevent theft during transmission.
（5） Construction and deployment considerations
Wiring specification:
Network cable selection: CAT5e or CAT6 unshielded network cable to avoid insufficient power supply or data packet loss due to poor quality network cable;
Installation of switch: it shall be placed in a ventilated and dry place (such as the cabinet beside the cash register), away from water and heat sources. Small stores can adopt wall mounted installation to save space.
Test acceptance:
Power on test: check the power supply status of equipment one by one, and confirm that the output voltage (44-57V) of PoE port is normal;
Network test: Ping command is used to test the delay (≤ 50ms) from the POS machine to the headquarters server, and iperf is used to test the video stream transmission bandwidth of the camera (no packet loss);
Remote management test: the headquarters platform tries to restart the store switch remotely, modify the port configuration, and confirm that the function is normal.
4、 Case reference (50 small chain convenience stores)
Equipment configuration: Each store deploys one 16 port Gigabit PoE switch (TP Link TL-SG1016PE)+one Gigabit router (Huawei AR1220E), and the headquarters deploys the H3C iMC cloud management platform.
Implementation effect:
Operation and maintenance cost: the operation and maintenance frequency of a single store is reduced from once a month to once a quarter, and the annual operation and maintenance cost is reduced by 60%;
Reliability: the equipment failure rate dropped from 8% to 1.2%, without business interruption caused by PoE switch failure;
Extensibility: When adding new stores, the headquarters will configure the parameters remotely and complete the deployment within one hour.
5、 Suggestions for later maintenance
Regular patrol inspection: monthly remote inspection of PoE power utilization rate (avoid exceeding 80%), port online rate, quarterly on-site inspection of network cable connectors, switch cooling;
Firmware upgrade: upgrade switch firmware in batches every six months according to the firmware update pushed by the manufacturer to fix security vulnerabilities;
Emergency plan: reserve 1-2 standby PoE switches, and guide the store staff to replace them remotely in case of equipment failure, so as to shorten the failure recovery time (≤ 4 hours).